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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8
votes
2answers
144 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
41 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
2answers
75 views

Applying a function to a column of a dataset [on hold]

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
37 views

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

I want to restructure a simple dataset. ...
2
votes
0answers
39 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
56 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
57 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: ...
-4
votes
1answer
57 views

Create a dataset containing a frequency sweep/chirp? [closed]

I need some help making mathematica make discrete values of a sine wave changing frequency from a to b. The dataset i want shall give discrete values of a sine wave which changes frequency. ...
0
votes
1answer
52 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
84 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
39 views
2
votes
1answer
43 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
34 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 ...
8
votes
0answers
89 views

Dataset with more than 16 “columns”?

A Dataset with 16 columns or less is shown in a nice way: ...
7
votes
1answer
130 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 ...
4
votes
2answers
82 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
180 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
79 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
167 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
59 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
106 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
275 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 ...
1
vote
1answer
86 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
89 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
156 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
49 views

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

Take an innocuous Dataset. ...
6
votes
2answers
84 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
119 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
68 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
85 views

Fill Dataset value with result of queries on other Datasets

I have a Dataset ...
1
vote
0answers
27 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
51 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
39 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
68 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
505 views

How to search Dataset to find all keys share same Value

If I have the following Dataset ...
4
votes
0answers
66 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
214 views

Change Values in Dataset under Condition

I have the following Dataset: ...
7
votes
1answer
112 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: ...
0
votes
1answer
43 views

Preserve Dataset for single column and single result instead of returning List

For consistency I would like the results of Select and similar operation on Datasets to always return a Dataset object. If you query a Dataset and the result is a single column or a single value a ...
7
votes
1answer
121 views

How can I export `Dataset` to a standard format?

I work with big data on AWS and scientific data in all the standard formats such as these... Is there any way to Import/Export Datasets or Associations to any of these non-primitive (txt, csv, ...
5
votes
2answers
128 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: ...
1
vote
1answer
58 views

Using a dataset of PredictorFunctions

I have been working with a dataset of predictor functions -- mainly so I can have more insight in to what the functions are doing and how they behave. Where I am struggling is using ...
0
votes
1answer
85 views

How to subset datasets in Mathematica 10 [closed]

I'm sorry if this is obvious but I can't find a way to select only a certain amount of columns of a dataset (or delete a certain amount of columns from a dataset) using the key of each column. I ...
2
votes
1answer
143 views

How to filter a dataset using Select and a parameter

I'd like to filter a Dataset using a parameter in Select, but so far I haven't been able to make it work properly. Say that I ...
1
vote
1answer
67 views

SemanticImport unable to properly read an Excel file with accented letters

Apparently SemanticImport fails to properly import Excel files when accented letters are present in the first (header) row. I'm using Excel 2013 on Windows 8.1 x64 ...
2
votes
2answers
116 views

KeyMap on a flat Dataset (i.e. Dataset@Association)

How can I go from Dataset[<|"A" -> 1, "B" -> 2, "C" -> 3|>] to ...
7
votes
1answer
109 views

Select From List of Nested Associations

I have an association: ...
0
votes
0answers
54 views

Define column types in a Dataset - Failure on append and Typesystem

I have a basic function that populates a Dataset according to user specified parameters. ...
1
vote
1answer
95 views

How would I obtain a list of column names in a Dataset?

I really love the addition of Dataset to Mathematica. I would like to write a basic utility function that exports a Dataset to Excel. Is there a way to get a list of column names from a Dataset?