Questions tagged [dataset]

Questions on the Dataset data type and related functionality introduced in version 10. Do not use for questions on data in more generic list format or data-manipulation questions generally.

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7
votes
0answers
80 views

How to navigate a large Dataset with keyboard short-cuts?

Update : Starting in 11.1 the navigation buttons are fixed to the left-hand side instead of being centered and don't jump around anymore. Starting with version 11.0 ...
6
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2answers
800 views

How to construct a dataset with lists as columns

So I know this should be pretty easy, but I cannot seem to find a solution anywhere, so thanks in advance for your help: I have three Lists (with numbers as ...
6
votes
4answers
373 views

Average dataset with many repetitions?

I have a dataset where each item is of the form: <|"p1" -> x1, "p2" -> x2, "r1" -> y1, "r2" -> y2|> The interpretation is this: ...
6
votes
4answers
710 views

SQL-like computation on Dataset: Aggregate function

Assume that I have this dataset a = Dataset[{<|"A" -> "A1", "B" -> 2|>, <|"A" -> "A1", "B" -> 3|>}] How can I get the total of Key["B"] ...
6
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2answers
804 views

Good way to create a similarity / distance matrix for a large dataset [duplicate]

I have a large dataset with rows (100k+) for products and columns for features. Now I want to create a similarity matrix with NormalizedSquaredEuclideanDistance. ...
6
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2answers
203 views

DeleteMissing level spec confusion

Given: titanic = ExampleData[{"Dataset", "Titanic"}] Why does this correctly delete Missing[] elements: ...
6
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4answers
206 views

GroupBy dataset values and length

I have a dataset, and I want to group by one of my columns, and then show the Length of another set of columns for each group. For example: ...
6
votes
1answer
185 views

Importing a Wikipedia Table as a Dataset?

I am trying to import this table from Wikipedia into Mathematica as a Dataset. The fields I'm interested are Name, ...
6
votes
2answers
456 views

Convert a huge txt-file into a dataset

My friend has this huge txt-log of sea levels. He wants to organize it into a dataset. After importing it this file a used StringSplit to separate it into rows, then to singular elements ...
6
votes
1answer
261 views

How to filter this nested list of Association

For example, I have the following data ...
6
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3answers
1k views

How to SemanticImport Multiple Excel Sheets

I have an Excel workbook with multiple sheets that I'd like to import into a dataset each. With Import I can target individual sheets by their name into a nested ...
6
votes
1answer
381 views

MapAt and generic Functions on Associations and Datasets

These are distinct but related questions about mapping functions to Associations and Datasets. Given: assoc = <| a -> 1, b -> 2, c -> 3|> And <...
6
votes
2answers
167 views

Dataset and Select with a SmoothKernelDistribution

This question is hopefully a case of stupidity on my side, but I just don't understand why this happens. I had code that worked perfectly fine for several weeks and gives an error now on Linux and Mac....
6
votes
2answers
331 views

Using Dataset with TimeObjects in EventSeries

I'm new to Mathematica, and while this is potentially quite easy, I'm having difficulty using TimeObjects in the EventSeries ...
6
votes
2answers
157 views

Dataset Query using Composition fails but RightComposition works - why?

V10.1 on Win764 Enterprise. In this (CORRECTED) example the two Queries may be compounded into one using RightComposition sucessfully... ...
6
votes
2answers
272 views

Apply an accumulative function to each column of a dataset

Given a dataset with many columns, how can apply a function (in this case Count[Missing_]) to each column? ...
6
votes
2answers
176 views

How to speed up Min of DateObjects?

I'm in version 10.0.1 using a Dataset to do some plots and things. For one of the plots I need to get the minimum date of a some filtered set of the ...
6
votes
1answer
149 views

MaximalBy[#, “votes”] & not equal to MaximalBy[“votes”]?

I'm looking at the results of the 2015 UK general election ...
6
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3answers
157 views
+50

Parsing Org-Mode Timelog Data

Suppose we have in ~/time-data/time-data.org the following data: ...
6
votes
2answers
529 views

How can I save a Manipulate's control settings to a dataset?

This is probably an extremely simple question. I have a manipulate that sets variables used to define an offset, amplitude, frequency and phase of a trigonometric function. ...
6
votes
1answer
87 views

Dataset: Failure when using functions that generate messages

Consider the dataset: data = Dataset[{<|"A" -> 1|>, <| "A" -> 2|>}] Define the function: ...
6
votes
1answer
121 views

Hold[Dataset[__]] not holding

Bug introduced in 10.0 and fixed in 11.0.0 With Hold[Dataset[Random[]]] instead of an expected Hold[Dataset[Random[]]] ...
6
votes
1answer
129 views

SemanticImport and zip files

I have looked through the documentation and don't see this addressed, but since some of you seem to have knowledge of undocumented features, I thought I'd ask. There is a zip file at http://www....
6
votes
1answer
223 views

Only String Keys supported in Dataset's Association Query?

fixed in 10.0.2 Given data: titanic = ExampleData[{"Dataset", "Titanic"}] This Association Query works: ...
6
votes
1answer
105 views

How to update values of particular keys efficiently

Say I have a list of Association, SeedRandom[45] test = Association[Table[i -> RandomInteger[30], {i, 6}]] <|1 -> 18, ...
6
votes
4answers
531 views

Selecting data from multiple columns

Mathematica has almost the following example in the documentation: ...
6
votes
2answers
131 views

JoinAcross question with combined keys

I would like to join associations in the following way. Say I have a dataset d1: ...
6
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1answer
111 views

Built-in (or Terse) Method to Combine and Transpose Datasets

From some calculations I have ended with Datasets of the form: ...
6
votes
1answer
261 views

Select query with named slot lookups?

Given this Dataset fragment (copy-paste friendly version at bottom) Can this query be simplified by referencing named slots directly in the ...
6
votes
1answer
164 views

How can Map be given access to the keys of a Dataset?

Consider an example Dataset: ...
6
votes
1answer
131 views

General question about data management

I am curating a small number of databases-actually I am not sure if they qualify as such; they are more like collections of-loosely-related data points; the problem is that they are growing over time; ...
6
votes
1answer
149 views

Explaining error when using Part inside Module in Dataset

I have a vague recollection of seen an explanation for this, but I can not find it, so it may be a false memory. Will delete if duplicated. Let ds be a simple <...
6
votes
1answer
101 views

Failure when exporting dataset with real-valued cells

Consider the following dataset: dat = Dataset[<| "A" -> 1, "B" -> 2|>]; ExportString[dat, "CSV"] It exports perfectly, with the expected result: <...
6
votes
1answer
730 views

Best practices with HDF5 and Datasets

I work with colleagues who rely on HDF5 as their data interchange format (largely exported from Python's Pandas). Of course we ...
5
votes
3answers
293 views

Changing Row Keys into Normal Rows

I have a dataset with column and row keys: ...
5
votes
3answers
686 views

How to create a table?

I have looked here at the forum and on the mathematica documentation center though still couldn't get it to work. I have two lists ...
5
votes
5answers
396 views

Vector operation on datasets

I have a dataset like: ...
5
votes
2answers
466 views

What are the Slot Names in a Dataset?

I have a dataset which are keyed on {"Item", "Hour of Day", "Value"}. In the examples, I noticed that it is possible to apply functions using such as ...
5
votes
2answers
422 views

Create a list of rules built from data set fields

I want to convert a dataset to a list of features and a list of target values, for use in Predict and also more generally. I know ...
5
votes
1answer
312 views

How to export a Dataset to JSON or CSV?

I am getting wolfram CDF format from this, ...
5
votes
2answers
229 views

How to select data of one column from a Dataset ( in this particular case )?

I use Mathematica 11.0.1 on Windows10, consider the following MWE: ...
5
votes
2answers
182 views

Fill Dataset value with result of queries on other Datasets

I have a Dataset ...
5
votes
3answers
190 views

Convert Matrix into a long form Dataset

I would like to convert a matrix into a dataset. The structure of the matrix is: ...
5
votes
2answers
281 views

How to lookup by a string key after GroupBy? Inconsistent data type handling

This is relates to a bug that was introduced in 10.0.0 and fixed in 10.0.1 It also relates to an issue that has yet to be corrected. After applying GroupBy to a ...
5
votes
2answers
438 views

Why this syntax for renaming columns in datasets?

Form the documentation of Dataset: ...
5
votes
1answer
361 views

LinearModelFit with Dataset

I have a rectangular dataset, initially created with SemanticImport of a CSV file and then manipulated. Rather surprisingly, ...
5
votes
1answer
249 views

Updated: Correct Formatting of Dataset (labeled columns and rows) for Predict v NetTrain?

Problem I can not seem to figure out the correct way of formatting Dataset to be used with predict. I am providing Mathematica's example, which works fine. I also am including an abitrary "dataset" ...
5
votes
1answer
102 views

Getting error message with Search on arXiv electronic preprint database

Just installed Mathematica v10.3 which has the new option to use arXiv, the electronic database. However I get an error message using ...
5
votes
2answers
237 views

Indexed Thread on dataset and list

I currently have a dataset, and I would like to add a column based on another list. For example: ...
5
votes
1answer
323 views

Filtering Query Nested Data (Dataset and Association)

I am trying to filter a nested Dataset. I have some data that looks like this (curated for this example): ...