I have some large data files that each contain 2 columns of data as shown below (strings in row are separated by spaces). I need to merge these files into one large file that contains 4 columns each separated by tabs. Is there an efficient built-in function that will let me do this using file streams without the need to read these large files in completely?
thanks
input1.txt
input2.txt
Desired output file
Sorry, text formatting (ironically) in the web app does not clearly illustrate the problem. See image below
thanks
So reading in the enclosed files and trying the join on the lists resulted in an error
file1List = ReadList[
Join[file1List , file2List , 2];
Expression {1836 -12,1012 -2661,-156 -2916,967 232,1224 1637,-1030 -754,-2002 -2651,-667 -1822,-267 -561,-[Ellipsis] 33,[Ellipsis] ,1292 1055,584 -469,584 -1311,1150 -974,-309 -767,-1949 -212,-719 1262,838 1754,-21 405} at position 1 is expected to have nonatomic subexpression at level 2. >>
Adding sample files to discussion.
Well, yes, according to you second posting I was assuming that your data are already in form of a matrix like so:
{{613, -112}, {1737,
392}, {1685, -176}, {1443, -813}, {891, -39}, {273, 1761}, {356,
2007}, {-8, -198}, {-882, -1634}} // TableForm
(*output: 613 -112
1737 392
1685 -176
1443 -813
891 -39
273 1761
356 2007
-8 -198
-882 -1634*)
Obviously this is not the case in your example …
Looks like the issue is that each row is currently a string and so the Join function is not getting the number of expected elements
A direct (but not very elegant) way could be:
ClearAll["Global`*"]
SetDirectory[NotebookDirectory[]];
input1 = Import["first.txt", "Data"];
input2 = Import["second.txt", "Data"];
result = Join[input1, input2, 2];
Export["result.txt",
StringReplace[
ToString[result], {"}, {" -> "\n", ", " -> "\t", "{{" -> "",
"}}" -> ""}]];
But I have to confess that this is not solving your primary question: This way the entire input files have to be red in first.
Henrik
Yes, here is another solution I came up with - last question, what is the best way to export this result to a file if we read everything in at once?
bobstephens
January 30, 2015, 11:34pm
10
sorry, missed the export to a file…thanks for your help
