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0answers
14 views

BUG? SemathicImport 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
60 views

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

How can I go from Dataset[<|"A" -> 1, "B" -> 2, "C" -> 3|>] to ...
6
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1answer
72 views

Select From List of Nested Associations

I have an association: ...
0
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0answers
37 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
67 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
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1answer
45 views

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

I would like to transform a table like ...
4
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3answers
97 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
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1answer
93 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
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1answer
163 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: ...
6
votes
2answers
124 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
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2answers
241 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
55 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
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0answers
52 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
59 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): ...
6
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2answers
189 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. ...
12
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1answer
247 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
186 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
141 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
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1answer
70 views

Dataset Query with condition on two subsequent rows

The following Dataset ...
2
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0answers
121 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
97 views

How to compare Histogram Data?

I'm using a Dataset ...
3
votes
1answer
163 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
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1answer
95 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
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1answer
68 views

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

Consider an example Dataset: ...
8
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4answers
198 views

How can a field be efficiently added to a Dataset?

Let's use the example Dataset: ...
5
votes
1answer
107 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 ...
4
votes
2answers
91 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
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3answers
125 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
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2answers
86 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
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2answers
166 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: ...
15
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3answers
328 views

Applying different functions to different columns of a Dataset

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

Dataset seems unable to handle ListDensityPlot and ListContourPlot

If I create a Dataset: ...
12
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2answers
213 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
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4answers
275 views

Finding totals in a Dataset

I have this Dataset: ...
10
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2answers
184 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
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0answers
79 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
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0answers
87 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
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1answer
94 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
324 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
163 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
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0answers
635 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" ...
10
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5answers
256 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
86 views

Select data from a Dataset [closed]

I have a dataset that looks like ...
7
votes
1answer
179 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
130 views

DeleteMissing level spec confusion

Given: titanic = ExampleData[{"Dataset", "Titanic"}] Why does this correctly delete Missing[] elements: ...
1
vote
1answer
73 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
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2answers
127 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
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1answer
110 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
91 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
210 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 ...