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3
votes
2answers
55 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... ...
1
vote
4answers
98 views

Mean duration between two specific data points

I have dataset such as: ...
5
votes
2answers
169 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
72 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 ...
15
votes
1answer
150 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
54 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
93 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? ...
1
vote
0answers
88 views

Using Periodogram to investigate the seasonality of the data

After asking how to get rid of the seasonality of this set of data, I'd like to ask how to investigate the seasonality in data using Mathematica. Which tool would you use to study seasonality? I.e. ...
4
votes
2answers
91 views

Deseasonalize the data of traffic growth for the past data

In another question (Using TimeSeriesForecast for forecasting the traffic growth) I asked to use the TimeSeriesForecast on this set of data the answer provided the plot with and without the ...
9
votes
2answers
268 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 ...
1
vote
0answers
29 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
66 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
81 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
154 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
45 views

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

Take an innocuous Dataset. ...
6
votes
2answers
78 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 ...
0
votes
2answers
81 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
67 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
77 views

Fill Dataset value with result of queries on other Datasets

I have a Dataset ...
1
vote
0answers
25 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
49 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
37 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
61 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
491 views

How to search Dataset to find all keys share same Value

If I have the following Dataset ...
4
votes
0answers
61 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
191 views

Change Values in Dataset under Condition

I have the following Dataset: ...
7
votes
1answer
108 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
32 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
110 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
116 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
81 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
134 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
65 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
113 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
105 views

Select From List of Nested Associations

I have an association: ...
0
votes
0answers
53 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
88 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?
3
votes
1answer
91 views

Transform a table (list of associations) to a flat association

I would like to transform a table like ...
4
votes
3answers
135 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"] ...
5
votes
1answer
110 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
174 views

10.0.2 breaks a recursive “trie” query

10.0.2 Dataset type system complication breaks a recursive trie constructor that worked in 0.1: ...
7
votes
2answers
157 views

Add column heads to a dataset

I have a dataset which I group an then calculate the maximum of an item. When done I get the desired result, but have no column heads. Here the example association (subset of my data): ...
7
votes
2answers
288 views

10.0.2 another Dataset type system (inference?) warning

Bug introduced in 10.0.2 The warning below seems unrelated to these issues: Did 10.0.2 break some forms for named slots? and 10.0.2 mapping Association to Dataset warning. First noticed w/ ...
3
votes
1answer
87 views

Multicolumn sorting with ordering functions and precedence

I am aware that the question of "how do I sort on a column" has been asked in various forms, most notably this one. While some powerful solutions have been presented, as far as I can find no one ...
0
votes
0answers
57 views

A more suggestive name for a useful utility Query?

Ideally this utility query to project only the named keys involved in the function mappings from relational tables with many columns would be built in the language. I use it a lot: ...
4
votes
1answer
83 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): ...
7
votes
3answers
276 views

Appending and Prepending columns to a dataset in 10.0.2.0

fixed in 10.1 (windows) I just experience a problem in prepending columns to a dataset. I did this a hundred times in 10.0.1.0 - no problems. Now it seems as if it is only possible to ...
12
votes
1answer
288 views

10.0.2 mapping Association to Dataset warning

In 10.0.2 ExampleData[{"Dataset", "Titanic"}][All, <| "gender" -> #sex|> &] Outputs the expected result, but also throws: MapAt::partw: Part ...
7
votes
1answer
201 views

Did 10.0.2 break some forms for named slots?

Since 10.0.2 some code that previously worked using named slots fail in very particular circumstances. Attchd screenshot shows the issue w/ a particular Dataset ...