Variables 🔗

Catalog 🔗

/datasets/{dataset_id}/variables/{?relative}

A Shoji Catalog of variables.

GET catalog 🔗

When authenticated and authorized to view the given dataset, GET returns 200 status with a Shoji Catalog of variables in the dataset. If authorization is lacking, response will instead be 404.

Array subvariables are not included in the index of this catalog. Their metadata are instead accessible in each array variable’s “subvariables_catalog”.

Personal variables are not included in the index of this catalog, although entities may be present at variables/{id}/. See Private Variables for an index of those.

Secure variables (those in the “secure” folder) are excluded from the variables catalog for users with view-only access. Hidden variables (those in the “hidden” folder) are included in the catalog for viewers. Clients are encouraged not to display hidden variables, but they are eligible for queries and for making filters and other assets, even for viewers.

Catalog tuples contain the following keys:

Name	Type	Description
name	string	Human-friendly string identifier
alias	string	More machine-friendly, traditional name for a variable
description	string	Optional longer string
id	string	Immutable internal identifier
notes	string	Optional annotations for a variable
discarded	boolean	Whether the variable should be hidden from most views; default: false
derived	boolean	Whether the variable is a function of another; default: false
type	string	The string type name, one of “numeric”, “text”, “categorical”, “datetime”, “categorical_array”, or “multiple_response”
subvariables	array of URLs	For arrays, array of (ordered) references to subvariables
subvariables_catalog	URL	For arrays, link to a Shoji Catalog of subvariables
resolution	string	Present in datetime variables; current resolution of data
rollup_resolution	string	Present in datetime variables; resolution used for rolled up summaries
geodata	URL	Present only in variables that have geodata associated; points to the catalog of geodata related to this variable
uniform_basis	boolean	Whether each subvariable should be considered the same length as the total array. Only on `multiple_response`
timestamped	boolean	Whether the variable has timestamped data associated with each entry. Only included if true.

The catalog has an optional query parameter:

Name	Type	Description
relative	string	If “on”, all URLs in the “index” will be relative to the catalog’s “self”

With the relative flag enabled, the variable catalog looks something like this:

Language-specific info:
JSON

{
    "element": "shoji:catalog",
    "self": "https://app.crunch.io/api/datasets/5ee0a0/variables/",
    "orders": {
        "hier": "https://app.crunch.io/api/datasets/5330a0/variables/hier/",
        "personal": "https://app.crunch.io/api/datasets/5330a0/variables/personal/",
        "weights": "https://app.crunch.io/api/datasets/5ee0a0/variables/weights/"
    },
    "specification": "https://app.crunch.io/api/specifications/variables/",
    "description": "List of Variables of this dataset",
    "index": {
        "a77d9f/": {
            "name": "Birth Year",
            "derived": false,
            "discarded": false,
            "alias": "birthyear",
            "type": "numeric",
            "id": "a77d9f",
            "notes": "",
            "description": "In what year were you born?"
        },
        "9e4c84/": {
            "name": "Comments",
            "derived": false,
            "discarded": false,
            "alias": "qccomments",
            "type": "text",
            "id": "9e4c84",
            "notes": "Global notes about this variable.",
            "description": "Do you have any comments on your experience of taking this survey (optional)?"
        },
        "aad4ad/": {
            "subvariables_catalog": "aad4ad/subvariables/",
            "name": "An Array",
            "derived": true,
            "discarded": false,
            "alias": "arrayvar",
            "subvariables": [
                "439dcf/",
                "1c99ea/"
            ],
            "notes": "All variable types can have notes",
            "type": "categorical_array",
            "id": "aad4ad",
            "description": ""
        }
    }
}

PATCH catalog 🔗

Use PATCH to edit the “name”, “description”, “alias”, or “discarded” state of one or more variables. A successful request returns a 204 response. The attributes changed will be seen by all users with access to this dataset; i.e., names, descriptions, aliases, and discarded state are not merely attributes of your view of the data but of the datasets themselves.

Note that using PATCH to modify “discarded” as a means of “hiding” a variable is deprecated: instead, move the variable into the hidden folder.

Authorization is required: you must have “edit” privileges on the dataset being modified, as shown in the “permissions” object in the dataset’s catalog tuple. If you try to PATCH and are not authorized, you will receive a 403 response and no changes will be made.

The tuple attributes other than “name”, “description”, “alias”, and “discarded” cannot be modified here by PATCH. Attempting to modify other attributes, or including new attributes, will return a 400 response. Variable “type” can only be modified by the “cast” method, described below. The “subvariables” can be modified by PATCH on the variable entity. “subvariables_catalog” is a URL to a different variable catalog and is thus not editable, though you can navigate to its location and modify subvariable attributes there. A variable’s “id” and its “derived” state are immutable.

When PATCHing, you may include only the keys in each tuple that are being modified, or you may send the complete tuple. As long as the keys that cannot be modified via PATCH here are not modified, the request will succeed.

Note that, because this catalog contains its entities (rather than collecting them), you cannot PATCH to add new variables, nor can you PATCH a null tuple to delete them. Attempting either will return a 400 response. Creating variables is allowed only by POST to the catalog, while deleting variables is accomplished via a DELETE on the variable entity.

Language-specific info:
JSON

{
    "element": "shoji:catalog",
    "index": {
        "9e4c84/": {
            "discarded": true
        }
    }
}

PATCHing this payload on the above catalog will return a 204 status. A subsequent GET of the catalog returns the following response; note the change in line 24.

Language-specific info:
JSON

{
    "element": "shoji:catalog",
    "self": "https://app.crunch.io/api/datasets/5ee0a0/variables/",
    "orders": {
        "hier": "https://app.crunch.io/api/datasets/5330a0/variables/hier/",
        "personal": "https://app.crunch.io/api/datasets/5330a0/variables/personal/",
        "weights": "https://app.crunch.io/api/datasets/5ee0a0/variables/weights/"
    },
    "specification": "https://app.crunch.io/api/specifications/variables/",
    "description": "List of Variables of this dataset",
    "index": {
        "a77d9f/": {
            "name": "Birth Year",
            "derived": false,
            "discarded": false,
            "alias": "birthyear",
            "type": "numeric",
            "id": "a77d9f",
            "notes": "",
            "description": "In what year were you born?"
        },
        "9e4c84/": {
            "name": "Comments",
            "derived": false,
            "discarded": true,
            "alias": "qccomments",
            "type": "text",
            "id": "9e4c84",
            "notes": "Global notes about this variable.",
            "description": "Do you have any comments on your experience of taking this survey (optional)?"
        },
        "aad4ad/": {
            "subvariables_catalog": "aad4ad/subvariables/",
            "name": "An Array",
            "derived": true,
            "discarded": false,
            "alias": "arrayvar",
            "subvariables": [
                "439dcf/",
                "1c99ea/"
            ],
            "notes": "All variable types can have notes",
            "type": "categorical_array",
            "id": "aad4ad",
            "description": ""
        }
    }
}

POST catalog 🔗

A POST to this resource must be a Shoji Entity with the following “body” attributes:

name
type
If “type” is “categorical”, “multiple_response”, or “categorical_array”: categories: an array of category definitions
If “type” is “multiple_response” or “categorical_array”: subvariables: an array of URLs of variables to be “bound” together to form the array variable
If “type” is “multiple_response” or “categorical_array”: subreferences: an object keyed by each of the subvariable URLs where each value contains partial variable definitions, which will be created as categorical subvariables of the array. If included, the array definition must include “categories”, which are shared among the subvariables.
If type is “multiple_response”, the definition may include selected_categories: an array of category names present in the subvariables. This will mark the specified category or categories as the “selected” response in the multiple response variable. If no “selected_categories” array is provided, the new variable will use any categories already flagged as “selected”: true. If no such category exists, the response will return a 400 status.
If “type” is “datetime”: resolution: a string, such as “Y”, “Q”, “M”, “W”, “D”, “h”, “m”, “s”, “ms”, that indicates the unit size of the datetime data.
folder: optional, a URL of a variable folder in the dataset into which the new variable should be placed. If omitted, the variable will be created on the root folder. Personal variables (with "private": true) cannot be placed in a folder; attempting to do so returns 400 status.

See Variable Definitions for more details and examples of valid attributes, and Feature Guide: Array Variables for more information on the various cases for creating array variables.

It is encouraged, but not required, to include an “alias” in the body. If omitted, one will be generated from the required “name”.

You may also include “values”, which will create the column of data corresponding to this variable definition. See Importing Data: Column-by-column for details and examples.

You may instead also include a “derivation” to derive a variable as a function of other variables. In this case, “type” is not required because it depends on the output of the specified derivation function. For details and examples, see Deriving Variables.

A 201 indicates success and includes the URL of the newly-created variable in the Location header.

Personal variables catalog 🔗

/datasets/{dataset_id}/variables/private/{?relative}

Personal variables are variables that, instead of being shared with everyone, are visible only by the user that created them. In Crunch, users with view-only permissions on a dataset can still derive variables of their own, just as they can make their own filters. Personal variables are not shown in the common variable catalog and are instead shown here.

Personal variables are “hidden” but not “secure”: if you create a filter or other asset using a personal variable and share it with other viewers of the dataset, they will be able to use the filter and make queries with it.

GET returns a Shoji Catalog of variables, as described above, containing those variables that are personal to the authenticated user. You may PATCH this catalog to edit names, aliases, descriptions, etc. of the personal variables. POST, however, is not supported at this endpoint. To create new personal variables, POST to the main variables catalog with a "private": true body attribute.

PATCH to this catalog also allows dataset editors to make variables personal by sending a Shoji catalog payload containing the URLs of the variables they wish to make personal, following the Folder API semantics.

The Shoji catalog should have empty objects as tuples.

Language-specific info:
JSON

{
    "element": "shoji:catalog",
    "index": {
      "http://app.crunch.io/api/datasets/abc/variables/xyz/": {}
    }
}

Hierarchical Order 🔗

/datasets/{dataset_id}/variables/hier/

Dataset global order containing references to all public variables.

GET 🔗

Returns a Shoji Order. “Hidden” variables are included in a special “__hidden__” group in the order. “Secure” variables and personal variables are not included.

PATCH 🔗

PATCH is deprecated: to move variables or make folders, use the folder API.

Will expect a Shoji Order representation containing a replacement or new grouped entities. This allows one to create new groups on the fly or overwrite existing groups with new ‘entities’.

The match happens by each group name and will overwrite the values of each group with the received one.

After PATCH any variable not present in the order will always be appended to the root of the graph.

PUT 🔗

PUT is deprecated: to move variables or make folders, use the folder API.

Receives a Shoji Order representation with a completely new graph. Any previously existing group will be eliminated and any new groups will be added. This will overwrite the complete set of current groups.

After PUT any variable not present on any of the groups will always be appended to the root of the graph.

Personal Variable Order 🔗

/datasets/{dataset_id}/variables/personal/

Unlike the hierarchical order, the personal variable order returns different content per user. Each user can add variable references to it including personal variables and will not be shared with other users.

The personal variable order defaults to an empty Shoji order until each user makes changes to it.

The allowed variables on this order are: * Any public variable available on the variable catalog * Any personal variable or subvariable for the authenticated user * Any subvariable of an array variable on the variable catalog

GET 🔗

Returns a Shoji Order for this user.

PATCH 🔗

Same as hierarchical order, receives a Shoji Order representation to overwrite the existing order. Personal variables are allowed here.

PUT 🔗

Behaves the same as PATCH.

Personal Variable Order Catalog 🔗

/datasets/{dataset_id}/variables/personal/variables/

The personal variable order comes accompanied with a catalog containing the variables present in the order’s graph. This provides access to the metadata for those variables.

This catalog is read-only, and has the same shape as the main variables catalog.

Language-specific info:
JSON

{
    "element": "shoji:catalog",
    "self": "https://app.crunch.io/api/datasets/5ee0a0/variables/personal/variables/",
    "specification": "https://app.crunch.io/api/specifications/variables/",
    "index": {
        "a77d9f/": {
            "name": "Personal variable",
            "derived": false,
            "discarded": false,
            "alias": "personalvar",
            "type": "numeric",
            "id": "a77d9f",
            "notes": "",
            "description": ""
        },
        "aad4ad/": {
            "name": "Private variable",
            "derived": true,
            "discarded": false,
            "alias": "privvar",
            "notes": "",
            "type": "text",
            "id": "aad4ad",
            "description": ""
        }
    }
}

Weights 🔗

/datasets/{dataset_id}/variables/weights/

GET 🔗

GET a shoji:order that contains the urls of the variables that have been designated as possible weight variables.

PATCH 🔗

PATCH the graph with a list of the desired list of weight variables. The list will always be overwritten with the new values. This order can only be a flat list of URLs, any nesting will be rejected with a 400 response.

If the dataset has a default weight variable configured, it will always be present on the response even if it wasn’t included on a PATCH request.

Removing variables from this list will have the side effect of changing any user’s preference that had such variables set as their weight to the current dataset’s default weight.

Only numeric variables are allowed to be used as weight. If a variable of another type is included in the list, the server will abort and return a 409 response.

“Secure” variables are not permitted as weight variables. Attempting to specify one will return a 409 response.

Language-specific info:
JSON

{
  "graph": ["https://app.crunch.io/api/datasets/42d0a3/variables/42229f"]
}

Warning

It is only possible to submit variables that belong to the main dataset. That is, variables from joined datasets cannot be set as weight.

PUT 🔗

Behaves the same as PATCH.

Entity 🔗

/datasets/{dataset_id}/variables/{variable_id}/

A Shoji Entity which exposes most of the metadata about a Variable in the dataset.

GET 🔗

Variable entities’ body attributes contain the following:

Name	Type	Description
name	string	Human-friendly string identifier
alias	string	More machine-friendly, traditional name for a variable
description	string	Optional longer string
id	string	Immutable internal identifier
notes	string	Optional annotations for the variable
discarded	boolean	Whether the variable should be hidden from most views; default: false
private	boolean	If true, the variable is only visible to the owner and is only included in the private variables catalog, not the common catalog
owner	url	If the variable is private it will point to the url of its owner; null for non private variables
derived	boolean	Whether the variable is a function of another; default: false
type	string	The string type name
categories	array	If “type” is “categorical”, “multiple_response”, or “categorical_array”, an array of category definitions (see below). Other types have an empty array
subvariables	array of URLs	For array variables, an ordered array of subvariable ids
subreferences	object of objects	For array variables, an object of {“name”: …, “alias”: …, …} objects keyed by subvariable url
resolution	string	For datetime variables, a string, such as “Y”, “M”, “D”, “h”, “m”, “s”, “ms”, that indicates the unit size of the datetime data.
derivation	object	For derived variables, a Crunch expression which was used to derive this variable; or null
format	object	An object with various members to control the display of Variable data (see below)
view	object	An object with various members to control the display of Variable data (see below)
dataset_id	string	The id of the Dataset to which this Variable belongs
missing_reasons	object	An object whose keys are reason phrases and whose values are missing codes; missing entries in Variable data are represented by a {“?”: code} missing marker; clients may look up the corresponding reason phrase for each code in this one-to-one map
timestamped	boolean	Whether the variable has timestamped data associated with each entry. Only included if true.

Category objects have the following members:

Name	Type	Description
id	integer	identifier for the category, corresponding to values in the column of data
name	string	A unique label identifying the category
numeric_value	numeric	A quantity assigned to this category for numeric aggregation. May be `null`.
missing	boolean	If true, the given category is marked as “missing”, and is omitted from most calculations. For logical operations, this makes the category “none/null/NA”.
selected	boolean	If true, the given category is marked as “selected”. For logical operations, this makes the category “true”. Multiple response variables must have at least one category marked as selected and may have more than one

Note

For variables with categories, you can get the “missing reasons” from the category definitions. You don’t need the “missing_reasons” body attribute.

Format objects may contain:

Name	Type	Description
data	object	An object with an integer “digits” member, stating how many digits to display after the decimal point when showing data values
summary	object	An object with an integer “digits” member, stating how many digits to display after the decimal point when showing aggregates values

View objects may contain:

Name	Type	Description
show_codes	boolean	For categorical types only; if true, numeric values are shown
show_counts	boolean	If true, show counts; if false, show percents
include_missing	boolean	For categorical types only; if true, include missing categories
include_noneoftheabove	boolean	For multiple response types only; if true, display a “none of the above” category in the requested summary or analysis
rollup_resolution	string	For datetime variables, a unit to which data should be “rolled up” by default. See “resolution” above.

Variable entities’ catalog attributes contain the folder member that points to the variable’s containing folder.

Additionally, the variable entity will hold references to related resources

Attribute	Description
catalogs.parent	Points to the variables catalog where this variable is contained.
catalogs.folder	Will indicate the URL of the folder where this variable is placed. If the variable is not on any folder (personal variables) then this attribute will not be present.
fragments.dataset	Points to the dataset this variable belongs to.
fragments.variable	In the case of subvariable entities, they will contain this reference pointing back to their parent variable URL.

All users with at least view permissions on the dataset may successfully GET all variable entities that are public, hidden, or personal (even to other users). Editing permissions are required to GET secure variables; users with view-only permission receive a 404 response if they GET a secure variable.

PATCH 🔗

PATCH variable entities to edit their metadata. Send a Shoji Entity with a “body” member containing the attributes to modify. Omitted body attributes will be unchanged.

Successful requests return 204 status. Among the actions achievable by PATCHing variable entities:

Editing category attributes and adding categories. Include all categories.
Remove categories by sending all categories except for the ones you wish to remove. You can only remove categories that don’t have any corresponding data values. Attempting to remove categories that have data associated will fail with a 400 response status.
Reordering or removing subvariables in an array. Unlike categories, subvariables cannot be added via PATCH here.
Editing derivation expressions
Editing format and view settings
Changing a datetime variable’s resolution

Actions that are best or only achieved elsewhere include:

changing variable names, aliases, and descriptions, which is best accomplished by PATCHing the variable catalog or folder, as described above;
changing a variable’s type, which can only be done by POSTing to the variable’s “cast” resource (see Convert type below);
editing names, aliases, and descriptions of subvariables in an array, which is done by PATCHing the array’s subvariable catalog;
altering missing rules.
changes to the variable’s timestamped parameter cannot be made at this time.

Variable “id” and “dataset_id” are immutable.

Example:

Language-specific info:
JSON

{
  "subvariables": [
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0008/",
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0007/",
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0009/"
  ],
  "subreferences": {
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0008/": {
      "alias": "subvar_2",
      "name": "v2_new_name",
      "description": null
    },
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0007/": {
      "alias": "subvar_1_new_name",
      "name": "v1_new_name",
      "description": null
    },
    "http://app.crunch.io/api/datasets/d4db9831e08a4922b054e49b47a0045c/variables/00000c/subvariables/0009/": {
      "alias": "subvar_3",
      "name": "subvar_3",
      "description": "new description"
    }
  }
}

POST 🔗

Calling POST on an array resource will “unbind” the variable. On success, POST returns 200 status with a Shoji View, containing the URLs of the (formerly sub-)variables, which are promoted to regular variables.

Trying to unbind a variable that is not an array will return a 400 response from the server.

A derived array cannot be unbound. It must first be integrated (by PATCHing null to its derivation expression, making it non-derived for good) and may then be unbound. Since this “undoes” the array, you should first see if there’s a way to refer to either a subvariable of the derived array, or one of the variables or subvariables from which it is derived, rather than unbinding.

DELETE 🔗

Calling DELETE on this resource will delete the variable. On success, DELETE returns 200 status with an empty Shoji View. Deleting an array deletes all its subvariable data as well.

Summary 🔗

/datasets/{dataset_id}/variables/{variable_id}/summary/{?filter}

A collection of summary information describing the variable. A successful GET returns an object containing various scalars and tabular results in various formats. The set of included members varies by variable type. Exclusions, filters, and weights may all alter the output.

For example, given a numeric variable with data [1, 2, 3, 4, 5, 4, {“?”: -1}, 3, 5, {“?”: -1}, 4, 3], a successful GET with no exclusions, filters, or weights returns:

Language-specific info:
JSON

{
    "count": 12,
    "valid_count": 10,
    "fivenum": [
        ["0", 1.0],
        ["0.25", 3.0],
        ["0.5", 3.5],
        ["0.75", 4.0],
        ["1", 5.0],
    ],
    "missing_count": 2,
    "min": 1.0,
    "median": 3.5,
    "histogram": [
        {"at": 1.5, "bins": [1.0, 2.0], "value": 1},
        {"at": 2.5, "bins": [2.0, 3.0], "value": 1},
        {"at": 3.5, "bins": [3.0, 4.0], "value": 3},
        {"at": 4.5, "bins": [4.0, 5.0], "value": 5}
    ],
    "stddev": 1.2649110640673518,
    "max": 5.0,
    "mean": 3.4,
    "missing_frequencies": [{"count": 2, "value": "No Data"}],
}

numeric 🔗

The members include several counts:

count: The number of entries in the variable.
valid_count: The number of entries in the variable which are not missing.
missing_count: The number of entries in the variable which are missing.
missing_frequencies: An array of row objects. Each row represents a distinct missing reason, and includes the reason phrase as the “value” member and the number of entries which are missing for that reason as the “count” member.
histogram: An array of row objects. Each row represents a discrete interval in the probability distribution, whose boundaries are given by the “bins” pair. An “at” member is included giving the midpoint between the two boundaries. The “value” member gives a count of entries which fall into the given bin. as well as basic summary statistics:
fivenum: An array of five [quartile, point] pairs, where the “quartile” element is one of the strings “0”, “0.25”, “0.5”, “0.75”, “1”, representing the min, first quartile, median, third quartile, and max boundaries to divide the data values into four equal groups. The “point” is the real number at each boundary, and is estimated using the same algorithm as Excel or R’s “algorithm 7”, where h is: (N - 1)p + 1.
min, median, max: taken from “fivenum”, above.
mean: the sum of the values divided by the number of values, or, if weighted, the sum of weight times value divided by the sum of the weights.
stddev: The standard deviation of the values.

categorical 🔗

The basic counts are included:

count: The number of entries in the variable.
valid_count: The number of entries in the variable which are not missing.
missing_count: The number of entries in the variable which are missing.
missing_frequencies: An array of row objects. Each row represents a distinct missing reason, and includes the reason phrase as the “value” member. The number of entries which are missing for that reason is included as the “count” member.

And the typical “frequencies” member is expanded into a custom “categories” member:

categories: An array of row objects. Each row represents a distinct category (whether valid or missing), and includes its id the _id member (note the leading underscore), and its name as the “name” member. The “missing” member is true or false depending on whether the category is marked missing or not. The number of entries which possess that value is included as the “count” member.

text 🔗

The basic counts are included:

count: The number of entries in the variable.
valid_count: The number of entries in the variable which are not missing.
missing_count: The number of entries in the variable which are missing.
sample: A sample of 5 entries of the data.

In addition:

max_chars: The number of characters of the longest value in the data.

Univariate frequencies 🔗

/datasets/{dataset_id}/variables/{variable_id}/frequencies/{?filter,exclude_exclusion_filter}

An array of row objects, giving the count of distinct values. The exact members vary by type:

numeric: Each row represents a distinct valid value, and includes it as the “value” member. The number of entries which possess that value is included as the “count” member.
categorical: Each row represents a distinct category (whether valid or missing), and includes its id the _id member (note the leading underscore), and its name as the “name” member. The “missing” member is true or false depending on whether the category is marked missing or not. The number of entries which possess that value is included as the “count” member.
text: Each row represents a distinct valid value, and includes it as the “value” member. The number of entries which possess that value is included as the “count” member. The length of the array is limited to 10 entries; if more than 10 distinct values are present in the data, an 11th row is added with a “value” member of “(Others)”, summing their counts.

Transforming 🔗

Convert type 🔗

/datasets/{dataset_id}/variables/{variable_id}/cast/

A POST to this resource, with a JSON request body of {“cast_as”: type}, will alter the variable to the given type. If the variable cannot be cast to the given type, 409 is returned. See next to obtain a preview summary of such a cast before committing to it.

Casting to datetime 🔗

From Numeric: Need to include keys: offset as an ISO-8601 date string and resolution which is one of the following strings:
Y: Year
Q: Quarter
M: Month
W: Week
D: Day
h: Hour
m: Minutes
s: Seconds
ms: Milliseconds
From Text: Need to include a format key containing a valid strftime string to format with.
From Categorical: Need to include a format key containing a valid strftime string to format with.

Casting from datetime 🔗

To Numeric: Not supported
To Text: Need to include a format key containing a valid strftime string that matches the variable values to parse with.
To Categorical: Need to include a format key containing a valid strftime string that matches the category names to parse with.

Array variables 🔗

Multiple Response: Not supported
Categorical Array: Not supported

/datasets/{dataset_id}/variables/{variable_id}/cast/?cast_as={type}

A GET on this resource will return the same response as ../summary would if the variable were cast to the given type. If the given type is not valid, 404 is returned.

Attributes 🔗

Missing values 🔗

/datasets/{dataset_id}/variables/{variable_id}/missing_rules/

A Shoji Entity whose “body” member contains an array of missing rule objects. POST a {reason: rule} to this URL to add a new rule. Rules take one of the following forms:

{‘value’: v}: Entries which match the given value will be marked as missing for the given reason.
{‘set’: [v1, v2, …]}: Entries which are present in the given set will be marked as missing for the given reason.
{‘range’: [lower, upper], ‘inclusive’: [true, false]}: Entries which exist between the given boundaries will be marked as missing for the given reason. If either “inclusive” element is null, the corresponding boundary is unbounded.
{‘function’: ‘…’, ‘args’: […]}: Entries which match the given filter function will be marked as missing for the given reason. This is typically a tree of simple rules logical-OR’d together.

Example:

Language-specific info:
JSON

[
  {
    "Invalid": {"value": 0},
    "Sarai doesn't know how to use a calculator :(": {"range": [1000, null], "inclusive": [true, false]}
  }
]

Warning

Missing rules consist on filter expressions that can only refer to the same variable ID where they are defined. Marking values as missing based on the contents of another column is not supported.

Subvariables 🔗

/datasets/{dataset_id}/variables/{variable_id}/subvariables/

GET 🔗

This endpoint will return 404 for any variable that is not an array variable (Multiple response and Categorical variable).

For array variables, this endpoint will return a Shoji Catalog containing a tuples for the subvariables. The tuples will have the same shape as the main variables catalog.

PATCH 🔗

On PATCH, this endpoint allows modification to the variables attributes exposed on the tuples (name, description, alias, discarded).

It is possible to add new subvariables to the array variable in question. To do so include the URL of another variable (currently existing on the dataset) on the payload with an empty tuple and such variable will be converted into a subvariable and added at the end.

In the case of derived arrays, an attempt to PATCH this catalog will return a 405 response. This is because the list of subvariables for this array is a function of its derivation expression. The correct way to make modifications to derived arrays’ subvariables is by editing its derivation attribute with the desired expressions for each of them.

Values 🔗

/datasets/{dataset_id}/variables/{variable_id}/values/{?start,total,filter}

A GET on this resource will return a JSON array of values from the variable’s data. The “start” and “total” parameters paginate the results. The “filter” is a Crunch filter expression.

This endpoint is subject to special authorization. Dataset editors may successfully GET values; users with view-only permissions can only access values if the viewers_can_export dataset setting is set to true. Unauthorized requests will return a 403 response. Note also that “secure” variables are only accessible to dataset editors, regardless of the viewers_can_export setting. If a user with view-only permissions attempts to access a secure variable entity, the API responds with 404 Not Found, so all resources contained below the entity URI (/datasets/{dataset_id}/variables/{variable_id}/) will also 404.