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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6
votes
1answer
61 views

Built-in (or Terse) Method to Combine and Transpose Datasets

From some calculations I have ended with Datasets of the form: ...
3
votes
1answer
61 views

How to Operate on a Dynamic Dataset?

I cannot operate on the Dataset I am dynamically filtering. Minimal example follows. ...
2
votes
1answer
79 views

How can I code markers for different groups' values over a period of time?

I have a 3-column dataset where I show the probabilities of winning of teams in different years (team name, year, prob.) I need to plot it with markers so the probabilities of each team can be ...
1
vote
1answer
84 views

How to make a 3D surface plot from DataSet

I am trying to plot some Aerodynamic data. I import my data like this: data = SemanticImport["roll-damp-due-to-roll-rate-semantic.csv"] The CSV file can be found here: data I want to make a 3D ...
3
votes
0answers
54 views

What's inside Dataset? [duplicate]

It seems that Dataset has rich structures in them, for example: ds = Dataset[{<|"a" -> 1, "b" -> "x", "c" -> {1}|>}]; TreeForm[dataset] Could ...
6
votes
2answers
155 views

How to access Dataset's metadata

A Dataset object has internal metadata. For example, let ds = Dataset[{<|"a" -> 1, "b" -> "x", "c" -> {1}|>}]; ...
10
votes
1answer
234 views

How to make datasets display correctly?

NB: The problem illustrated below is truly ubiquitous. I hope the examples given below are sufficiently different to demonstrate this fact, and to discourage answers that hinge on the details of the ...
2
votes
2answers
87 views

How to reduce each column of a dataset?

Given a simple dataset like this one: ...I want to apply some reduction function (like Total or MinMax) to each column ...
7
votes
1answer
89 views

How to create dataset with ordered and hierarchically-grouped rows?

The (toy-example) dataset plots consists of 12 rows, the first two of which are shown below: I want to arrange the plots shown in the ...
1
vote
2answers
61 views

How to read rows and headers separately into a dataset?

Suppose that the information for constructing a dataset is split over two separate files: one file contains the numeric data, and a second file contains the names of the columns. Is there a simple ...
2
votes
0answers
32 views

Evaluating same expression twice gives two distinct answers. Problem with Dataset?

Consider the followind Dataset: d = Dataset[<|1 -> Missing[], 2 -> 2.0|>] Now evaluate d[All, 1 + # &] It ...
1
vote
0answers
72 views

Numbers not treated as numbers

I'm apologize for the stupidity of this question, but I've run out of ideas. I have some data saved in a mx file. When imported, MM isn't treating the values as numbers. For instance: ...
3
votes
2answers
94 views

Building a classifier with complex strings as variable

I'm attempting to build a classifier using complex strings as one of the variables. Modified Titanic data as an example: ...
6
votes
1answer
77 views

SemanticImport and zip files

I have looked through the documentation and don't see this addressed, but since some of you seem to have knowledge of undocumented features, I thought I'd ask. There is a zip file at ...
4
votes
1answer
88 views

Upvalues for Missing do not work with Dataset

Consider the following Dataset: d = Dataset[<| 1 -> Missing[], 2 -> 1.0, 3 -> 4.0 |>] And the following Upvalue for Missing: ...
3
votes
1answer
70 views

Duplicate rows with multiple entries

I have a huge dataset, which looks similar to this: ...
6
votes
2answers
125 views

Good way to create a similarity / distance matrix for a large dataset [duplicate]

I have a large dataset with rows (100k+) for products and columns for features. Now I want to create a similarity matrix with NormalizedSquaredEuclideanDistance. ...
1
vote
1answer
71 views

Create a Dataset object, Association or SparesArray from a matrix [closed]

I need to make queries and operations on a large dataset. What is the easiest way to add keys to matrix so that it is transformed to a dataset, which can later be used to make queries? Let's take ...
3
votes
1answer
70 views

Add columns with dummies and specific headers to dataset

I got a dataset that looks like the following example: ...
2
votes
2answers
81 views

Group Datasets and take minimum/maximum

Good Morning I have the following dataset: And I try to reach this output: key: only one row per key text: join all texts of the rows with the same key (but no duplicates) min: take the lowest ...
0
votes
0answers
27 views
1
vote
2answers
54 views
0
votes
0answers
19 views

DO Button: convert databin entry from String to Reals

I am learning to use the Wolfram databins and DO Button and DO Note apps for a personal project. The sample code I am using as the Recipe is: ...
2
votes
1answer
123 views

Classifying images in mass with URLs and CSV file

I'm looking to train a image classifier with a large number of examples and categories (30,000 & 100). I would then import a file of image URLs that need to be classified, and export the results. ...
5
votes
2answers
323 views

How to construct a dataset with lists as columns

So I know this should be pretty easy, but I cannot seem to find a solution anywhere, so thanks in advance for your help: I have three Lists (with numbers as ...
4
votes
2answers
134 views

Use Select to filter a dataset's sublists

In the following Dataset, I want to use Select to display only rows, which contain numbers in column ...
3
votes
1answer
138 views
1
vote
0answers
34 views

MedianDeviation upsets Dataset in 10.3.1

This seemingly innocent piece of code seems to choke the interpreter somewhere... ...
0
votes
0answers
38 views

Changing default display behaviour for Dataset

I have a function (whose code is in this site) to display Dataset in a more convenient way. To the extent that I never use the default one. I find myself constantly ...
2
votes
1answer
79 views

Help with Time-Seried dataset

I can't seem to figure out the best way for directly inputting interpolated values into a dataset. I turn to your expertise for guidance. So, I have a multi-year time-series dataset. Column 1 is time ...
11
votes
1answer
193 views

Getting data from FRED

Mathematica V10.4 supports a service for connection to FRED. If you create a connection with fred = ServiceConnect["FederalReserveEconomicData"] (you need to ...
1
vote
0answers
44 views

Save experimental data within notebook. Is it possible? [duplicate]

I'm trying to use Mathematica for all my scientific needs as much as I can, so I can learn. When I want to plot my experimental data using Mathematica, I've been Import[] and plot data sets. However, ...
6
votes
3answers
156 views

Enabling JoinAcross to merge non-joined keys

I've come across the following "JoinAcrossMerge" sufficiently often to wonder if Dataset's semantics can offer a natural implementation. Say I have 2 datasets ...
6
votes
4answers
260 views

Average dataset with many repetitions?

I have a dataset where each item is of the form: <|"p1" -> x1, "p2" -> x2, "r1" -> y1, "r2" -> y2|> The interpretation is this: ...
4
votes
0answers
93 views

How can I add column-rearrangement-by-mouse-dragging to my dataset display function?

A subject that I seem to take at heart... I was expecting an upgrade of the default Dataset display in MMA 10.3.1. It did not happen. Among the features I would have liked to see improved is a ...
17
votes
0answers
133 views

V10's TypeSystem - what are these function useful for? [closed]

The symbols in the TypeSystem` context are clearly used for working with Datasets, but they seem powerful. I was hoping that someone could help explain how they work and is they are useful for ...
3
votes
0answers
70 views

Map level inconsistencies with Missing values [closed]

Negative Level specs interact with Missing values, eg: ...
9
votes
2answers
116 views

A subtlety in Query

Let us consider a simple Dataset: ds=Dataset[{<|"a"->12,"b"->4|>,<|"a"->7,"b"->8|>,<|"b"->3|>}] Column "b" is easy to find: ...
3
votes
0answers
75 views

Data Interpolation of deaths by date

I am working with an ebola dataset from Guinea, 2014:(http://currents.plos.org/outbreaks/article/estimating-the-reproduction-number-of-zaire-ebolavirus-ebov-during-the-2014-outbreak-in-west-africa/). ...
4
votes
2answers
150 views

With “named row” nested Datasets: How to Select or Filter rows by row key with criteria from another Dataset?

After some calculations and grouping I have a Dataset similar to the following form: ...
1
vote
0answers
51 views

How to show complete dataset? [duplicate]

<|{{1, "u"}, {1, "u"}} -> {{0}}, {{1, "d"}, {1, "u"}} -> {{2 (f - g Cos[p])}}|> // Dataset gives All the items are incomplete. How to show ...
3
votes
1answer
98 views

How to get name of “named row” in Dataset for function applied to each row

After some calculations and a GroupBy I have a Dataset that is structured like this. ...
4
votes
2answers
114 views

Remove rows from dataset using query

MyDataSet[Select[#point[Fsr] == 1 &]] returns the row I want to delete, now I am trying what looks to me the most logic command to remove these rows, which is ...
1
vote
1answer
109 views

How to convert a column of a Dataset into a list [closed]

I'm loving the fact that Mathematica has finally implemented the Dataset feature, but I'm still struggling a little with it. I have a Dataset that contains a bunch of functions for different diseases ...
3
votes
1answer
66 views

Blocking Dataset`$ElisionThreshold doesn't work

I would like to define a simple function to automatically show all rows in a Dataset. Based on Taliesin Beynon's answer, I tried the following trivial snippet: ...
7
votes
1answer
127 views

Writing code which generates a function to append many columns to a dataset

I love datasets in Mathematica. Say I have one that looks like this: ...
4
votes
1answer
90 views

Getting error message with Search on arXiv electronic preprint database

Just installed Mathematica v10.3 which has the new option to use arXiv, the electronic database. However I get an error message using ...
3
votes
1answer
87 views

DeleteMissing doesn't match in Association tables

DeleteMissing doesn't work in Association tables: ...
11
votes
1answer
159 views

The equivalent of dplyr mutate with Dataset

In R, there is a package "dplyr" that works on data.frame objects, which is one of the origins of the Mathematica Dataset construct. One of the things dplyr can do is "mutate" the columns of a ...