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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16
votes
2answers
160 views

Dataset vs an association of associations

Associations with a record structure (e.g., a flat table) can be organised in one of two main ways. First as a list of associations, which is also used in the case of Mathematica's data set ...
0
votes
0answers
36 views

How to Export a mixture distribution to .json file

I would like to export the following mixture distribution mathematica found for my dataset to .json file ...
13
votes
2answers
193 views

Exporting Dataset to WDX format fails

I reported this to WRI support. Tracking number is CASE:3368636 Official answer is: Thank you for contacting Wolfram Technical Support. This is a known issue and our developers are working on a ...
4
votes
1answer
72 views

Query Dataset to check if row contains any from a set of values

For a given keyless dataset, I can query to return the rows whose columns contain a specific value. For example: ...
7
votes
4answers
228 views

How to iterate over the columns of a Dataset?

I have a Dataset with a simple structure, like this: ...
5
votes
2answers
186 views

Cutting away points that are not resonances

My situation is as follows. I have a whole bunch of data that I need to fit, which tends to look like this picture: As can be seen, there's three dips (resonances) and a whole bunch of noise around ...
5
votes
2answers
97 views

Dataset breaks multi-character StringSplit

Given ds = Dataset[{"a b", "c-d"} ] multi-character StringSplit is broken with Dataset ...
10
votes
2answers
120 views

Lookup with default broken in Dataset

Given an Association, ...
4
votes
2answers
142 views

Transpose can't handle fractions

Related to this question, why can't Transpose handle fractions? (Note the doc pages for Transpose hasn't been updated for v10) ...
4
votes
0answers
63 views

Why is Transpose Dataset slow in one direction

Transpose is faster when it distributes Keys at the 2nd level of a Dataset than when it factors them out. ...
4
votes
1answer
98 views

ANOVA test on dataset

I have a dataset with 3 groups and two variables. I want to do ANOVA test on the three groups for each variable. Does anyone know how to do this? ...
3
votes
0answers
48 views

Export to MX seems to corrupt the in-memory Dataset

I have a function that does a large number of calculations (by calling out to other smaller functions), and then builds a large Dataset object. Then I do two ...
11
votes
2answers
189 views

Simple way to concatenate Dataset columns

Consider these two datasets: d1 = Transpose@Dataset[<|"a" -> Range[5]|>]; d2 = Transpose@Dataset[<|"b" -> Range[5, 1, -1]|>]; {d1, d2} What's ...
1
vote
1answer
58 views

Plotting datasets using ErrorListPlot

I am trying to make list plots with the ErrorListPlot function. I have two datasets (ds1 and ds2) of which one plots nicely (ds1) and the other just give blank plots. I cannot see any difference in ...
2
votes
1answer
98 views

Applying a function to a column of a dataset [closed]

Functions can easily be applied to columns of datasets, as in the documentation it is shown. Now I want to apply a function with parameters to a column, but I get a list rules. E.g. ...
1
vote
1answer
44 views

Conditional Drop of a Key based on a test of the Value

I want to restructure a simple dataset. ...
3
votes
0answers
51 views

Applying functions to irregularly distributed Keys in Association lists

This Q is related to this one, but now refer to the situation as irregularly distributed Keys in lists of Associations: ...
2
votes
1answer
62 views

Applying Switch and Which to mixed-Key Association lists

Given an Association list w/ a common Key but also some distinct ones: ...
0
votes
1answer
74 views

A Query using Select and Quiet fails but Select by itself works

This is closely related to the question here, the key difference is that here data is structured as nested Association rather than a flat list: ...
0
votes
1answer
62 views

Dataset fails on StringMatchQ warning due to Missing value

Missing values are a pain mathematically and computationally in general not just in WL, but I think this problem is more related to Dataset handling of warnings: ...
0
votes
2answers
87 views

Is it possible to sum the results of a Map - Apply?

I am fairly new to functional programming and would like to replace a For[] loop that sums the results over a Dataset. This may be a bit different since the ...
1
vote
1answer
51 views
2
votes
1answer
50 views

Do Dataset functions get applied to rows in order?

If I have a dataset ds and perform an operation such as ds[All, f] does f get applied in the order the rows exist (the order they were placed into the dataset or as the result of a SortBy clause) or ...
1
vote
0answers
43 views

Multiplying two sets of data (x,y values, but different x density) followed by integration of the product

I've been trying to do this by myself today, but no luck yet. Please, see attached image. Basically, I do have two data sets A (x1,y1) and ...
11
votes
1answer
147 views

Dataset with more than 16 “columns”?

A Dataset with 16 columns or less is shown in a nice way: ...
7
votes
1answer
152 views

How would I use Map on a Dataset column?

I am somewhat new to functional programming. To improve the performance of a package, I would like to re-write a package in a functional style. I have the following ...
5
votes
2answers
100 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... ...
5
votes
2answers
188 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 ...
3
votes
1answer
92 views

Is there a way to embed a data set in a notebook?

I'm relatively new to mathematica programming. I have a data set (currently a table in a .csv file). I would like to share this notebook with colleagues either as a notebook, or (even better) as a ...
17
votes
1answer
189 views

Why do lookup times in Dataset and Association differ by orders of magnitude?

Consider the following three data structures: a list of rules, an association, and a dataset: ...
0
votes
1answer
63 views

Need Query form to extract Min and Max DateList values for PlotRange from a Dataset

(* SUMMARY - In a Dataset holding DateList entries, how do I extract a minimum and maximum DateList value to pass into DateListPlot's PlotRange specification? See QUESTION further below *) (* Sample ...
4
votes
2answers
113 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? ...
9
votes
2answers
286 views

Why can I not replace a Dataset using a rule?

Simple replacement of a Dataset object does not seem to follow the expected behavior... Dataset[{}] /. _Dataset->1 Returns the empty Dataset not 1 as I would ...
2
votes
0answers
35 views

Encourage SemanticImport to assume numbers?

I would like to import a CSV without specifying the data type of each column before hand. SemanticImport almost does it, but doesn't appear to recognize numeric ...
2
votes
1answer
122 views

Dataset: sort rows in descending order of first column

I am new in the Mathematica community and I have a probably easy question for you regarding how to sort a dataset as the following so that I have sorted the values in the fist row descending from 44 ...
0
votes
1answer
102 views

Simultaneously fitting two data sets to two functions is too slow [closed]

I have to fit two data sets to two functions(eps1,eps2) with same parameters (w0,f,g) Initially, I know only one function ...
2
votes
2answers
161 views

Entropy of the elements of a general data set

I have the following data set, and wish to track the evolution of the entropy of each element within the set. I have evaluated the entropy for some elements, but how does one evaluate the entropy of ...
1
vote
0answers
55 views

What is the “Origin” rule for in a Dataset?

Take an innocuous Dataset. ...
6
votes
2answers
87 views

How does Grid operate on Dataset?

The documentation (10.0.2) indicates that Grid can be used to display a Dataset; the section in guide/ComputationWithStructuredDatasets labelled 'Dataset Presentation'. However simply invoking ...
1
vote
2answers
131 views

Delete rows from a dataset

I have a dataset built from a call to SemanticImport("/data.csv", Delimiters -> ",") with data.csv of the form: ...
0
votes
2answers
74 views

Select over many lists with changing selection criteria

I have many individual timeseries I am trying to align and compute the mean and other statistics for. The problem I am having is that I am only interested in aligning a particular part of each ...
2
votes
2answers
90 views

Fill Dataset value with result of queries on other Datasets

I have a Dataset ...
1
vote
0answers
31 views

Expose TimeObject fractions of a second and user-defined formatting

The default TimeObject formats (doc page), don't display fractions of seconds: ...
-1
votes
1answer
57 views

Exporting Data file in .dat format [duplicate]

Here I'm solving two simultaneous to get different values of the roots depending upon another variable 'x'. I've written up to the following using 'Find Root' ...
0
votes
0answers
45 views

GeoLabels/Tooltips in Geographic Plots from Dataset

I am looking to plot a list of list of regions, and attach some data to the GeoLabel. All the data is stored right now in a Dataset that contains entries of the form ...
4
votes
2answers
71 views

Using GatherBy with a DataSet's header designation instead of First

Using the code, where ds is data formatted into a Dataset GroupBy[ds, First] // TableForm I get a table that I wanted, but I was wondering if I could somehow use ...
14
votes
7answers
535 views

How to search Dataset to find all keys share same Value

If I have the following Dataset ...
4
votes
0answers
70 views

What is Association[Rule[“ID”,number ] and how it is used

I am trying to understand the structure and the use of Dataset and I came across something new to me. First check this example: ...
13
votes
2answers
261 views

Change Values in Dataset under Condition

I have the following Dataset: ...
7
votes
1answer
117 views

Why does an inert ReplaceAll modify this Dataset?

I cannot see any reason for this behavior besides a bug, but I've been wrong before so I put it before the community: ...