Questions about the Text based file format CSV (Comma Seperated Values). Questions include, but are not restricted to, importing from and exporting to this file format.
6
votes
1answer
113 views
Working with a CSV data file with 100 millions rows (and 30 columns)
I am new to working with large datasets.. Currently I am struggling to upload a "big data" file into Mathematica. The file is in the CSV format and has 14GB. There are 100 millions of rows and 30 ...
0
votes
0answers
23 views
Imported CSV output shows null with actual data value; can't plot data [closed]
I'm trying to do a simple import of 2-column CSV data. the first column is integers from 0 to 100 and the second column is various decimal values. The problem is that except for the first pair of ...
1
vote
1answer
41 views
How to separate rows with commas in imported CSV
I imported a CSV file that uses commas as its delimiter, but some fields also contain commas. When I import the file into Mathematica as follows
...
0
votes
0answers
18 views
Different behaviour of List when imported from MX and CSV
On a sort of related question here, I noticed something odd about the behaviour of List.
When
Import["myCombinAnalysis.MX"]
...
4
votes
1answer
60 views
Import specific columns from a large amount of CSV files
I'm looking to import the 4th column of data from a few hundred CSV files that I have stored in various folders. I have been able to import all CSV files from a given directory through use of:
...
2
votes
2answers
60 views
Convert CSV data for use with CandleStickChart
can anyone show me an example of how to import a CSV file and produce and CandlestickcChart using the imported data.
I have tried
...
6
votes
2answers
90 views
Importing a string such as “3d456” from a CSV file causes trouble
I have a CSV file I'm importing with Import and it consistently crashes Mathematica. It turns out the culprit is one particular value of an ID field that was ...
3
votes
1answer
250 views
Appending to a .csv file
I have a selection of Lists of data which are in the same format, and if I Export them all to CSV at the same time I get a nice ...
0
votes
1answer
47 views
Import floating numbers from Google spreadsheets in CSV
For some reason when importing some floating numbers, Mathematica does not interpret them correctly. For example this spreadsheet:
https://docs.google.com/spreadsheets/d/...
1
vote
1answer
41 views
separating a `ReadList` of a CSV file into columns using `Case`
I have a really large file and would like to determine the pattern required for separating the columns by the different headers.
I attempted to use Cases but it's ...
0
votes
0answers
51 views
Problems importing data file
I'm having trouble importing a CSV file.
The CSV file doesn't have simple dimensions, some rows may have many more columns than others.
From my imported file I cannot access the ...
2
votes
1answer
142 views
Empty field “\”\“” In CSV Import Problem
I have a huge CSV data, with the format like this:
"5";"8";"2803";
"";"6";"2793";
I import the data with this code:
...
5
votes
0answers
104 views
How to change Export default in 11.2?
To achieve the same CSV output as from previous versions Export requires the option "TextDelimiters" -> "". Presumably the ...
0
votes
0answers
75 views
Text-analysis: Import CSV without stringquotes
I have a large amount of text-files. I want to compare these text-files based on common 'words'. I export the output of my analysis as a CSV file. When I import the same file I get all seperate words ...
1
vote
1answer
56 views
read data from file having different format numbers
I'm trying to process my bank's data, which is always formed by lines with 5 fields separated by semicolons.
Until recently, it used to write the numbers in the "1234,56" format, and I processed them ...
9
votes
3answers
790 views
Mathematica 11.2 Import Statement Produces Errors & Truncates CSV Data Created in 11.1
Bug introduced in 11.2.0
TL;DR
Issue 1 (bug): Import of CSV files with column specification fails when "HeaderLines" or ...
0
votes
0answers
49 views
How to explicitly set horizontal coordinates when plotting multidimensial Table using DateListPlot?
I'm trying to plot a multidimensial data table which is stored in csv file.
Like so:
...
1
vote
3answers
170 views
Import of CSV with OpenRead
I have tried to use OpenRead for my application as it appears to be less of a burden on the memory.
I OpenRead a .csv file to extract coordinates in the form {x,y} in the following way
...
1
vote
1answer
199 views
Exporting weather data as CSV or XLS file
I am relatively new to mathematica, and sorry if this question is too simple.
I am trying to export weatherdata to a csv or xls file.
...
6
votes
2answers
163 views
SemanticImport fails with CSV when last column is ALL empty
(MMA v11.1.1)
I have many empty fields in my CSV files and I couldn't understand why sometimes SemanticImport just failed to recognize the headers. I just find out ...
0
votes
2answers
452 views
Plotting data imported from CSV file
So I have some data in a csv file that I want to plot. The csv file has several columns. I want to plot one of the columns as the x axis and all the other columns on the y axis. I have used the Import ...
2
votes
0answers
42 views
Import fails silently [closed]
In brief, an Import of a largish (11G) tsv file fails silently. I'm looking for ways to troubleshoot the problem further, and/or work around the failure.
Details
...
0
votes
0answers
187 views
1
vote
0answers
137 views
Export number as formatted numeric value, not string
Some related questions include here.
Is there a way to format numbers for export in CSV or JSON as numbers - not strings - with a specified number of decimal places and no exponentials?
Is output ...
1
vote
1answer
292 views
Import image saved as CSV file [closed]
I have saved my image file from ccd camera as a CSV file. How can I plot this file to get my image back? My file is here.
4
votes
1answer
327 views
How to make Import[…, “Table”] not convert strings to numbers and not convert numbers to strings?
Bug introduced in 8 or earlier and persisting through 11.2.0
I have to to use r = Import["foo.txt", "Table", "FieldSeparators" -> {","}] since my data is Table ...
2
votes
1answer
90 views
Importing integer codes with leading zeros as strings from CSV [closed]
Importing CSV seems to automatically cast to integer what are supposed to be integer codes.
This causes problems when some codes have a prefix of a variable number of "0" and have to be matched ...
3
votes
2answers
459 views
I have a bigdata CSV file as a single table of five columns and almost 10 million rows
I need to examine the bigdata file with a database/DBMS and have used MS Office 365/Access successfully so to do, import and query. I have also tried, many times, to open a MMA 10.4 database link ...
4
votes
1answer
272 views
Importing data from a CSV file — a string is being converted to a number
I'm very much a newbie, so please forgive any errors or stupidity.
I have a csv file named csvfile. Its, contents confirmed by me, by looking at the contents in a ...
3
votes
0answers
85 views
SemanticImport extremely slow with “Number” format
With the following definition:
col = "num\n" <> StringRiffle[Table[i, {i, 1000}], "\n"];
I do not understand why the ...
3
votes
1answer
675 views
Removing quotes from fields after import of table [closed]
I would like to remove quotes around fields when importing a csv table. It should be simple, but I cannot find any answer.
My data is in the format ...
0
votes
1answer
126 views
Import hangs on a 15 MB CSV file [closed]
Trying to import a small (15 MB) CSV file and the Import command is either not responding or responding very slowly. Watching the memory usage of the Mathematica kernel when initializing the command ...
0
votes
1answer
401 views
How to export CSV with fixed delimiter and specific format specifier
I would like to export an array to a csv file with a specific type of delimiter and a specific notation of the numbers (in this case scientific notation 1.234E-02).
How can I achieve this in a ...
3
votes
1answer
609 views
StringSplit on comma but ignore commas in quotes [closed]
I'm importing CSV files and some of the fields include quoted text with commas as part of the field, rather than as a field separator. What is the syntax (or alternative method entirely) to import ...
1
vote
2answers
153 views
Reading simple data csv file containing “e” and “i”
I can't find a way to properly read a csv file containing complex numbers in the following form:
...
0
votes
2answers
217 views
make a surface plot that changes with time from csv data
How can I plot 4d data from a csv, using a slider for the 4th variable? I would like to use var1 and var2 as x-y corrdinates, var3 as surface height, and var4 as the time slider.
If I have a csv <...
-1
votes
2answers
271 views
4
votes
2answers
425 views
Excluding Specific Rows Using Import[…]
As the question states, I'm trying to import a .csv file but I would like to exclude certain rows (points which I know are bad data).
This is easy when the points ...
0
votes
1answer
166 views
Combining first 5 columns from CSV file into AbsoluteTime date
Thanks in advance for all your help.
I need to import data from a CSV file that looks like :
(easier to read in excel)
I would like to convert the data into timestamps by creating a Table with 2 ...
1
vote
2answers
715 views
Problem fitting a exponential function to data points [closed]
finale edit: i found someone who solved my problem via matlab. therefore i wont try out the proposed solutions now, but wont delete my question in case someone might have use for the proposed ...
1
vote
1answer
91 views
Creating table out of two lists
I have two lists:
fi = { -0.25, -0.21 , -0.1, ...}
fv = { 2, 3, 4, ...}
Now I want to export these in form of a CSV file, which should look like this:
...
-1
votes
4answers
473 views
Import vs ReadList CSV file with Currency Values
A testing file with the specified format can be downloaded from here
Let's read a few lines from this file
...
4
votes
3answers
1k views
Importing CSV with multiline text fields
Bug introduced in 8 or earlier and fixed in 11.2.0
Here is a valid CSV:
a1,b1,c1,d1,"e1
e1
e1"
a2,b2,"c2
c2
c2",d2,e2
It has two rows and five columns, and ...
3
votes
1answer
1k views
How to properly export string columns in csv?
How can I make sure that certain string columns of a matrix I want to export get properly formatted? That is, all quotes escaped, and every string wrapped in quotes. Here's what happens now:
...
0
votes
1answer
121 views
Import a 3D CSV file results in the wrong dimensions
I exported a some of my data to a file, the data looks like this before the export
...
3
votes
2answers
455 views
Troubles importing date and time from CSV file
I'm trying to import CSV file with the following format:
20150803 00:00:01.649,1.09675,1.09678
using this code:
...
35
votes
5answers
6k views
How can I import a huge CSV file quickly?
I have two CSV files, each one is around 1 GB of data. When I use Import["file.csv"], it takes a very, very, long time to import the data. So how can I accelerate ...
1
vote
1answer
2k views
Export data from Array to *.csv without curly brackets
I have a couple of *.csv files containing data from several experiments. From those, two columns shall be extracted each, to form a new list. This process shall be automated to collect all the data ...
-3
votes
1answer
275 views
Loading CSV file is slow
I'm trying to import a CSV file that contains the latitude and longitude of some USA routes, but the import process is very slow and Mathematica spent about 10 min importing it.
A link to the file ...
2
votes
1answer
397 views
Convert spreadsheet (Excel) to *.csv during import
I have long lists of data in spreadsheets and have the problem that Mathematica crashes regularly during import of the .xlsx files. Is it possible within Mathematica to take a certain tab of a .xlsx ...
