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Questions tagged [dataset]

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.

3
votes
1answer
34 views

Calculations on columns (column by column) in Dataset

Dataset from doc: ...
6
votes
2answers
385 views

Convert a huge txt-file into a dataset

My friend has this huge txt-log of sea levels. He wants to organize it into a dataset. After importing it this file a used StringSplit to separate it into rows, then to singular elements ...
1
vote
1answer
40 views

Two ways of obtaining differential distribution using Mathematica do not match

Consider a set of data dataset = {{x1,y1},{x2,y2},...} It contains ~200000 rows. I would like to obtain the pdf for x. I can do this, for example, using two ways:...
1
vote
1answer
25 views

How to display properly Dataset with index column?

I'm trying to construct and display properly DataSet. Everything works fine, except the index column('Year'). I'm trying different variants: Example 1: ...
3
votes
2answers
68 views

Using DeleteCases with a defined function with two arguments as a pattern

I am trying to manipulate some large datasets in Mathematica. I have plotted the data, and I would like to be able to easily remove points from the dataset, and it's fairly easy to identify the x-...
3
votes
1answer
54 views
6
votes
2answers
151 views

How to read .npy file in Mathematica?

I have a .npy file which is created by numpy of Python as below:- ...
0
votes
0answers
43 views

How to handle exceptions and failures in Mathematica?

In python I can write fallback values like: ...
1
vote
0answers
23 views

one Dataset from multiple csv files

In one folder I have many csv files, all sharing an identical header. I can use SemanticImport to produce a Dataset from each ...
1
vote
1answer
46 views

Matrics manipulations

this is a basic question in Mathematica, I hope to get help to resolve it, How I can extract elements from matrics for example I have ...
0
votes
1answer
52 views

Deriving a list of time differences from a column in a dataset and appending the list as a new column

I know it's a beginner question, but I've struggled with it for some time now and can't find a solution. I have a dataset consisting of timestamps, where I've managed to compute the time differences ...
1
vote
1answer
27 views

FromDMS conversion within a Mathematica Dataset

I have a simple dataset for which I am attempting to modify so that values for two columns, entitled “LATITUDE” and “LONGITUDE” can be converted from a Deg-Min-Sec format, expressed as a String (ie “9°...
1
vote
0answers
58 views

How to display more of the Dataset depth?

Consider the following Dataset. ...
1
vote
3answers
90 views

Group by using a key [duplicate]

I have a dataset which looks like this: I want to create another dataset such that I get the count of A1flag for each userId, i.e., 5311->2, 5313->2. I tried the following code ...
4
votes
0answers
31 views

How to preserve Dataset's pagination inside Manipulate?

I'm having troubles preserving automatic pagination provided by Dataset when it is embedded in a Manipulate. Consider the ...
2
votes
1answer
43 views

How can empty fields in a csv file be set to Missing when importing as a Dataset?

When importing a csv file with empty fields as a Dataset, the empty fields are set to zero-length strings (""). There is an option, ...
1
vote
0answers
36 views

How do I Select when the key of an association is a multi-word string [closed]

I have imported some survey responses into a Dataset. I now want to select those rows where the response to "participant type" == "Virtual". I discovered that this ...
1
vote
2answers
42 views

Changing values in a column of a Dataset using a Do loop

I'm trying to use "Do" to change the entries in a column of a dataset using two adjacent columns. When I simply assign i and execute the lin for each value of i, it works but when I enclose it in Do, ...
2
votes
1answer
105 views

Deleting missing values from a dataset

I wanted to create a dataset of all UFO sightings in April of 2018. The AssociationThread doesn't want to work, because some of the entries are missing value, what ...
0
votes
1answer
59 views

The specific GeoMarker from DataSet [closed]

With reference to this related topic, I have a map (called EKB): EKB= The coordinates of the map corners: ...
1
vote
1answer
72 views

How do I formulate a query on the data returned by ResourceData? [closed]

I struggle to answer the following question: Use ResourceData["New Orleans Slave Sales 1856-1861"] to answer the following question: How many rows in which the ...
4
votes
2answers
48 views

Simple dataset query

Why does taking a Part fail in a Dataset query function when there is an operation in the index argument? ...
1
vote
2answers
94 views

Importing Excel File as Dataset

This might be a basic question but I couldn't get it to work. I have a dataset in Excel that I import to mathematica using ...
3
votes
1answer
61 views

What's the best way to import such dataset?

https://www.ocr.org.uk/Images/400305-large-data-set-lds_1-h630-2018-h640-2018-2019-pre-release-data-mei.xlsx What's the best way to import such dataset? I have tried to use ...
4
votes
0answers
57 views

Is this the most idiomatic way to convert matrix into dataset?

Is this the most idiomatic way to convert matrix into dataset? (for Mathematica 10 or higher) I was kind of hoping this would work: ...
0
votes
0answers
22 views
3
votes
2answers
77 views

Is there a straightforward way of naming CSV/TSV columns when importing as a dataset?

I have data in TSV (tab-separated) files. The thing is, columns do not have headers. Importing data is as easy as ds = Import["foo.tsv", {"Dataset"}]; ...
2
votes
3answers
113 views

ScientificForm in Dataset

Via SQL query I produce a list ...
1
vote
0answers
32 views

Issues with Manipulate (or variable assignment)

I am working to take a large manipulator I have built and generalize it, but I keep running into some variable assignment issue. I made a short example of my issues below: Set up: ...
1
vote
1answer
44 views

Building a data frame from a list of lists of lists

OK, let's say we have a following list of lists of lists: ...
3
votes
2answers
111 views

Importing an Excel file as a structured dataset

I need to import an Excel file as a dataset with row and column headers, and the following option using "Dataset" does not work. However, I can import the Excel file using "Data" option as a list ...
2
votes
1answer
85 views

How to set up SortBy columns in Dataset dynamically?

Given a dataset like this: ...
1
vote
0answers
46 views

what is equivalent of dataset when using with APIFunction? [duplicate]

I am researching on building a backend for website using Wolfram. APIFunction is great to use, but I can't figure out how should I store data like using dataset in a local notebook when using ...
13
votes
3answers
336 views

Deleting noisy data from a plot (manually) and export the best remaining data

I have the following temperature time-series. As you can see it contains very very noisy points in some periods (Fig.A). I tried to approach the best data(the black one in the center) based on the ...
1
vote
2answers
129 views

Select items from dataset with GUI using checkbox and Togglebar : empty results with DynamicModule

I have a dataset or records, I want to select records with a GUI (manually ticking on the selected item). Then, I want to apply functions to those items (not in this question). I think Im almost ...
2
votes
0answers
41 views

Calculate the precision@k in Classify

I am interested to measure a precision@k. The Classify function provides a build in an option for that or an elegant approach to calculate this without the need to ...
5
votes
2answers
83 views
1
vote
3answers
100 views

Most efficient way to replace/ update the values multiple rows and columns of a Dataset

Suppose we wish to replace the cols "b" and "c" of rows 3 to 5 in the following dataset to b and c respectively: ...
1
vote
1answer
38 views

Dynamic DateListPlot with multiple categories backed by DataSet

I have a DataSet that contains records with: an "activityName" string representing the kind of activity a "duration" value representing minutes a DateObject representing a date and time named "...
3
votes
1answer
90 views

TakeList of a Dataset

Check this out I want to split the Dataset for graphical reasons, like creating a nice composition on a page, TakeList should ...
2
votes
1answer
66 views

Replacing values in a dataset

Could someone explain why ...
0
votes
1answer
121 views

Aggregate function problem

I use a function to do something similar to a SQL sum. I've asked about simplifying it in another post. I'm still using this function and it works well for aggregates like ...
2
votes
1answer
67 views

Filter rows in nested Association / Dataset using Select

The Dataset I am working with has the following nested structure. ...
1
vote
1answer
128 views

Problem importing from HDF5

I'm trying to import an item from a valid HDF5 file, but I get this error: I can read the metadata, but cannot import the actual tensor dataset: And yet it's not an issue with the file's data - as ...
4
votes
1answer
215 views

How to export a Dataset to JSON or CSV?

I am getting wolfram CDF format from this, ...
4
votes
2answers
206 views

How can you replace a column of a Dataset with another column or list?

Consider the dataset below with a "x" and a "CH 1" column: How can I replace the "x" column with a new set of data? For example, how could I replace "x" with values starting from 0 and incrementing ...
4
votes
1answer
59 views

Operator form for Histogram of multiple datasets?

I would like to plot a histogram for multiple datasets in a dataset query, but can't quite seem to make it work in operator notation: ...
1
vote
1answer
129 views

How to make an Association of Assocations [closed]

As a learning exercise I’m trying to convert some data we have from spreadsheets into an association of associations. However, I’ve only managed to format two different associations, a key of the ...