Re: Importing CSV (comma separated values) files?

*To*: mathgroup at smc.vnet.net*Subject*: [mg13798] Re: [mg13765] Importing CSV (comma separated values) files?*From*: "Sherman.Reed" <sherman.reed at worldnet.att.net>*Date*: Fri, 28 Aug 1998 04:18:21 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Joe, I have done the following, very successfully, for about ten years: 1. save the file in csv format: 2. read the file with a text editor and delete all the commas (in unix I use vi, in dos I use edit, or ?) 3. then I read the file into Mathematica. Sherman C. Reed sherman.reed at worldnet.att.net ---------- > From: Joe Gwinn <gwinn at ma.ultranet.com> To: mathgroup at smc.vnet.net > To: mathgroup at smc.vnet.net > Subject: [mg13798] [mg13765] Importing CSV (comma separated values) files? > Date: Monday, August 24, 1998 4:07 AM > > I have been trying to convince Mathematica 3.0.1 to ReadList an ordinary > CSV spreadsheet file, without luck. It finds the file OK, then > complains of an unspecified "syntax error" while reading a number. No > useful information is presented; all one knows is that it failed. > > The file contains 240 lines, each line containing 240 non-negative > integer values separated by commas. There are no decimal points or > plus/minus signs. The values range fom 0 to 255. For the record, this > is an output file from a CCD instrumentation TV camera used to measure > fiber optic nearfield flux distributions. > > I have played with various combinations of RecordLists, WordSeparators, > and Number, to no avail. > > Even though 240x240= 57,600 entries, Mathematica was not out of memory. > The kernel has 25 MB, and the Front End has 10 MB, and the two > memory-use thermometers were less than 25% full. If I take the same > file and edit it into Mathematica nested-list format and turn it into a > Mathematica notebook, Mathematica handles the data quite well, so the > problem is purely with the import function. > > > The actual output follows: > > raw2Ddata = > ReadList[fullpath,Number,RecordLists->True (*, > WordSeparators->{","}*)]; Read::"readn": > "Syntax error reading a real number from \!\(\"FWB 4 GB:Gigabit \ > Ethernet:Of\" \\[Ellipsis] \"urs:2D Image Data:50M_OFL.IMG\"\)." > > All I can guess is that Mathematica expects numbers with decimals, and > isn't getting the decimals. If that's true, it's a problem, because > the instruments don't do decimal numbers. Is there an "Integer" > declaration for ReadLists? "Integer" didn't work. > > > Anyway, has anybody managed to get this to work, or have any > suggestions? > > > Also, a comment for Wolfram: Mathematica should be able to read and > write Microsoft Excel "text" format, and also CSV formatted files > directly and efficiently, using built-in functions, to enable access to > the vast range of scientific instruments and analysis packages, and > databases. The present manual process is very slow and clumsy. > > > And, the error message needs some work. One easy and very helpful trick > is to echo the offending line, and then put a line of ^^^ symbols under > the offending token: > > Now is the t1me for ... > ___________^^^^_________ > Number found where only letters were expected. > > > Joe Gwinn