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2
votes
1answer
32 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
44 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
40 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): ...
5
votes
2answers
132 views

Appending and Prepending columns to a dataset in 10.0.2.0

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 append/prepend one column at a time. ...
11
votes
1answer
204 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 ...
6
votes
1answer
159 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 ...
3
votes
3answers
101 views

Rearranging a Dataset

When processing a larger Dataset I came up do a point where I want to form a dataset with culumn heads from an intermediate structure. Here is an example of this structure: ...
2
votes
1answer
60 views

Dataset Query with condition on two subsequent rows

The following Dataset ...
2
votes
0answers
113 views

Fitting an implicit function to data with error bars [closed]

I am trying to fit a Brillouin function to the peak intensity of neutron scattering data, for which I have an error bar for each data point. For this the program has to fit a function, for which the ...
3
votes
1answer
89 views

How to compare Histogram Data?

I'm using a Dataset ...
2
votes
1answer
122 views

Trouble with Datasets in Version 10.0.1

Almost every morning, when I start my work, I observe the same problem as already mentioned here: Dataset Mathematica 10.0 and here: Dataset: cannot reproduce a basic example. A bug? I opend this new ...
1
vote
1answer
90 views

Select last occurence of key in dataset

I have a large Dataset filled with data from a SQL DB. I sort the set via name and date with the SelectBy function and get ...
4
votes
1answer
55 views

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

Consider an example Dataset: ...
7
votes
4answers
157 views

How can a field be efficiently added to a Dataset?

Let's use the example Dataset: ...
5
votes
1answer
96 views

How to get data from DB into dataset with keys

I'm a Mathematica newbie and I have the following problem: I connect to a Oracle DB and read out a set of variables, further on I want to histogram some of the variables. A Dataset seems to be the ...
3
votes
1answer
61 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 ...
5
votes
3answers
115 views

How to pass options to ListPlot when using a DataSet?

Still learning the new DataSet feature, I would like to create a ListPlot where the color of the points is to be determined by a ...
4
votes
2answers
78 views

GroupBy and MaximalBy to create a new Dataset

I'm looking for a neater way to achieve this, which to me looks awkward and suggests that I am missing something... Given a Dataset... ...
10
votes
2answers
148 views

Transform Dataset so it can be used as training set for Classify

Trying to learn the new Dataset features, I am playing with the iris dataset: ...
14
votes
3answers
310 views

Applying different functions to different columns of a Dataset

Suppose I have different functions: Total, Mean and Max and the following ...
16
votes
3answers
362 views

Dataset seems unable to handle ListDensityPlot and ListContourPlot

If I create a Dataset: ...
12
votes
2answers
180 views

Show More Rows of Dataset

Dataset rather conveniently truncates the display of a dataset that has many rows. However, occasionally, I would like to show more of a dataset without having to ...
6
votes
4answers
261 views

Finding totals in a Dataset

I have this Dataset: ...
10
votes
2answers
173 views

Temporal database reconstruction in mathematica

<EDIT> after some internet research I found the database domain that deals with this kind of thing: Temporal Databases. I think my question therefore becomes how to reconstruct a temporal ...
1
vote
0answers
77 views

Why does my dataset lose its typesetting when I add columns?

I've tried multiple methods of adding and removing columns to a dataset, but it seems no matter which way I choose I can't get the data to typeset as a table. Here's my initial dataset: 1) ...
0
votes
0answers
71 views

How to open *.sif files with Mathematica

While I am processing my data collect from an Andor EM-CCD, I find it diffcult to import the file into mathematica. I think mathematica can open this kind of files since that Matlab can open it. So if ...
4
votes
1answer
86 views

Casting Dataset internal type from Assoc to Struct

Using: planets = ExampleData[{"Dataset", "Planets"}]; The full form of this projection displays the internal type def: ...
4
votes
3answers
318 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 ...
2
votes
2answers
145 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 ...
8
votes
0answers
623 views

Dataset in Mathematica 10.0.1

Wolfram pages "Mathematica Quick Revision History" in Mathematica 10.0.1 release says: "New operators and compositions of operators enabled for associations functions such as Dataset and Query" ...
9
votes
5answers
231 views

Applying a function to a Dataset column conditional on another slot's value

How to apply a function to a column conditional on another slot's value? The Dataset documentation show only how to apply a function to named slots independently. The ...
1
vote
1answer
79 views

Select data from a Dataset [closed]

I have a dataset that looks like ...
6
votes
1answer
175 views

Incorrect result while using SemanticImport for CSV file import

I might use this incorrectly. I want to use a .csv file that (as list) looks like: ...
6
votes
2answers
126 views

DeleteMissing level spec confusion

Given: titanic = ExampleData[{"Dataset", "Titanic"}] Why does this correctly delete Missing[] elements: ...
1
vote
1answer
63 views

ReadList or any other command to read in blocks of very large numbers

I have a data file, data.txt, having following data: ...
8
votes
2answers
124 views

Missing: KeyGroupBy?

Especially in tree-structured data, keys and values, being two sides of the same coin, frequently interchange roles. The ability to aggregate by value but not by key upsets the balance. How to ...
6
votes
1answer
106 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: ...
2
votes
2answers
90 views

How to make functions from datasets

I have a csv that encodes the results of plugging certain parameters (say, A and B) into certain functions (say, ...
6
votes
1answer
189 views

Import iTunes xml data and convert it into a dataset or table

I have an xml file with song data from iTunes (https://dl.dropboxusercontent.com/u/1012958/iTunes%20Library.xml) and I'd like to import it to Mathematica to do some statistics. I get an XMLObject like ...
6
votes
2answers
156 views

Advanced SQL-type select statements (filtering) on Datasets

I'm trying to improve on mathematica's handling of datasets. I'm currently writing this function that should do the following. Suppose I have a dataset with columns, e.g. ...
9
votes
3answers
135 views

Problem constructing Association tables with some operators

fixed in 10.0.2 First, set up the example Dataset from the documentation: titanic = ExampleData[{"Dataset", "Titanic"}]; ...
7
votes
1answer
149 views

Group dataset on two keys (GroupBy)

I would like to group the elements of row c of the following dataset according to the values in the columns a and b. That is Go from here To here And then I would like to print this on a grid, ...
8
votes
2answers
143 views

Change dataset key name

Using the example in the documentation, how would I make a new dataset with the key "b" changed to key "h". ...
5
votes
2answers
148 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 ...
8
votes
1answer
102 views

Possible Bug in ProbitModelFit when used in a Dataset

Since upgrading to Mathematica 10 on Mac OSX I have come across a number of instances of this error, which occurs using Probit and Logit model fit. A bit of googling show this is something to do ...
3
votes
2answers
121 views

Simplifying a time-series segmentation Query

This query segments a time-series and filters out dropout frames. Can it be simplified - ie, made more readable? ...
9
votes
2answers
156 views

Does Dataset round? [duplicate]

I'm importing the following Excel file: My code and its results are: ...
14
votes
1answer
295 views

Export dataset to JSON

I'm experiencing a weird issue. Consider a dataset defined like this: dataset = Dataset[{<|"a" -> 1, "b" -> 2|>, <|"a" -> 3, "b" -> 4|>}]; ...
7
votes
0answers
142 views

Median of Dataset in Mathematica 10

I'm having trouble calculating the median of a Dataset[] in Mathematica 10. The situation is as follows. Consider a dataset that was defined as follows: ...
5
votes
1answer
321 views

How to split a Dataset into training and testing for machine learning?

Suppose I have iris data In the Dataset Format. How to split the iris data Into training and testing for Machine learning? For example,Transform the data for Classify.