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.

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Increase number of rows displayed by Dataset [duplicate]

Is it possible to increase the number of rows (records) displayed by Dataset? By default, only the first few rows are displayed. Which, in many cases, is fine. Especially for large datasets. ...
3
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1answer
66 views

Join Datasets based on row index

I would like to join two Datasets based on their row index. Unlike ordinary columns, a row index does not have a name. Single Row Index ...
2
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1answer
46 views

Sort Dataset by Row index after GroupBy

I would like to sort my Dataset by its row index. Unlike an ordinary column, this index does not have a name. ...
2
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1answer
35 views

Picking rows from a list

Let's consider the following list data = {{1}, {}, {1,1,1}, {1,1}, {1}, {1,1}, {1}, {2,1,1}, {3,1}, {3,2,1}, {}} As we can see, some rows have 0, other 1, other ...
4
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4answers
169 views

Padding a column of lists

I have data in the the form of a table, whose one column is the following ...
9
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1answer
111 views

How can weighted averages be calculated for a Dataset summarized with GroupBy

I would like to compute market-value weighted stock prices grouped by sector from a Dataset but can't figure out how to apply ...
0
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1answer
68 views

Using Semantic Import to do an Excel-like VLookUp using Mathematica

I'm following an example provided in the following Stack Exchange Link but, using a different approach. My data is contained in an Excel workbook called "Input Workbook.xlsx" as shown here: I ...
12
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1answer
141 views

Using Select on Dataset with missing keys

I have a very large dataset with about a million entries with up to 75 keys each. Across the whole dataset about half of the keys are blank. In order to reduce filesize, I have used the following ...
2
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0answers
60 views

How to display rotated columns names in dataset?

Consider the following minimalist Dataset: ...
5
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3answers
284 views

Changing Row Keys into Normal Rows

I have a dataset with column and row keys: ...
1
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1answer
76 views

How to build a structured data table

I'm going straight to the task; I start with the following list of Florida counties: ...
3
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2answers
36 views

Dataset query for upper levels

I have the following data set: ...
3
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2answers
65 views

Row Keys in Datasets: JoinAcross row keys; Demoting or deleting row keys

I want to combine two datasets that share row keys but have different column keys. Visually, this looks like a JoinAcross on the row keys to me, but the column of row keys doesn't appear to be named. ...
7
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2answers
92 views

Creating a new Dataset column using a map from a second Dataset

Say I have two datasets: one is a detailed list of events, and one is a coarse list of events. I want to add a column to the detailed list from the coarse list (for the purposes of sorting). For ...
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0answers
42 views

Wikipedia Edits History: how to split edit history and comments

I am trying to import Wikipedia Edit History. The code that I am using is the following: ...
1
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1answer
59 views

Taking the largest 10 items of a dataset? [closed]

With a dataset like: How can one take the top 10 items (largest by FileSize in this case)?
8
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1answer
134 views

Datasets and Time Values: Filtering and Plotting

After struggling for a few weeks, I have accumulated a few examples of challenging date-related operatations with datasets. Some I have partial solutions; others I cannot yet do. The resources on ...
2
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0answers
37 views

Parsing Org-Mode Timelog Data

Suppose we have in ~/time-data/time-data.org the following data: ...
0
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1answer
30 views

Import multiples images from FITS format

I want to import multiple images from url that are within a .txt but I am getting error, is not a valid file, directory, or URL specification ...
2
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1answer
86 views

Scraping 2020 Polling Data w/Mathematica?

Is there a way to use Mathematica to scrub the latest ("RCP average") polling data for each of the 2020 Democratic Primary candidates?
1
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1answer
42 views

Applying Function to Ambiguous Dates in a Dataset

I have a large Dataset with a few columns that contain ambiguous date strings in a variety of formats. I am wanting to reformat these so they are all the same. ...
2
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0answers
79 views

Converting Datasets into EntityStores: best practice?

The advent of the family of *edEntityClass functions in V12 looks very promising. Dataset and its related queries are ideal for ...
2
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2answers
74 views

How to get company dataset in original currency?

I have obtained the financial data of a company using Entity["Company", ...]["Dataset"]: ...
1
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2answers
67 views

Apply function with multiple arguments to column in dataset

I have a Dataset that requires some cleaning. Let's consider this data: ...
0
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1answer
69 views

Correct double distribution function for the following dataset

Consider a dataset data-angles-gamma-factors.txt having the form {{x1,y1},{x2,y2},...}. Each row represents an event with values x,y; all events have the equal ...
0
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1answer
69 views

Interpolation function error: The quality of the underlying mesh is too low

Consider a dataset BplustoPiXlight.dat (alternative link). I import it and try to interpolate: ...
0
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0answers
22 views

How do I apply GeoRegionValuePlot to a grouped Dataset?

I have a database like the one under this question which I transform into a Dataset by applying ...
1
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2answers
69 views

Create Dataset from lists

Let's assume I created the following dataset: ...
1
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1answer
64 views

How to join N datasets with common headers?

I am new to Dataset. I'm trying to join many datasets, naively trying to use Join, but I think I'm not using it correctly, or ...
1
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1answer
43 views

Why UnitCovert doesn't work with Fit?

I need to find the Hubble constant (Ho) in light years, from some data, the exercise tells me that the constant of the hubble is the slope of the line. data: r1 is in MegaParsecs. ...
4
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1answer
65 views

Inconsistency in getting Keys, Values and Query for nested Rules

Querying nested Rule expressions of the form a -> v -> b // FullForm Rule[a,Rule[v,b]] for ...
4
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2answers
101 views

How to pull out the underlying query syntax being used by dataset?

Consider the following dataset. titanic = ExampleData[{"Dataset", "Titanic"}] If I use the lookup syntax of the dataset like following it creates an equivalent <...
3
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1answer
51 views

Calculations on columns (column by column) in Dataset

Dataset from doc: ...
6
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2answers
421 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
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1answer
46 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
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1answer
34 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: ...
2
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2answers
77 views
3
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2answers
80 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
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1answer
67 views
7
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2answers
314 views

How to read .npy file in Mathematica?

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

How to handle exceptions and failures in Mathematica?

In python I can write fallback values like: ...
2
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0answers
32 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
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1answer
62 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
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1answer
55 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
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1answer
30 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
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0answers
65 views

How to display more of the Dataset depth?

Consider the following Dataset. ...
1
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3answers
99 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
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0answers
38 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
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1answer
87 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, ...