exptim, imptim (Frequency Domain Identification Toolbox)

Read/write ELiS time domain data vectors and/or ELiS time domain files.

tvect = exptim(timevect,xt,yt)
tvect  exptim(timevect,xt,yt,i,expno,...
        filename,comments,fdate,digitnum)
[timevect,xt,yt] = imptim(tdat)
[timevect,xt,yt,expno,comments,fdate] = imptim(tdat,expi)

Description

exptim exports data of one experiment (or several experiments) to a vector in the workspace, and/or to a (perhaps already existing) time domain data file. The output argument tvect is the vector containing the same data as would be sent to a *.tnt file.

timevect is the vector of sampling time instants, xt is the input vector (or array for multiple inputs), and yt is the output vector (or array for multiple outputs). Each vector must be a column vector. The data belonging to different experiments have to be put under each other. xt or yt may be empty, but both of them have to be given.

expno is the total number of experiments, i contains the number(s) of the actual experiment(s). If several experiments are given, they must be denoted by successive numbers. If i is empty, the default is i = [1:length(xt(:,1))/length(timevect)].

The string filename contains the name of the output file. If this name has no extension, exptim extends it by '.tbn'. If the extension is .tbn, the result will be a binary file, else an ASCII file. If the extension is '.tnt', no text is sent to the ASCII file, only data.

The file will be created in the active subdirectory or folder. If filename is empty, no file will be written.

If a file is read or written, the most important values will be displayed on the screen, unless a global variable expimpmessages with value 'no' is defined.

When exporting the data of experiment No. 1, any file with the same name will be deleted.

comments is a string with eventual comments (optional), and fdate is the date (and time) string (also optional). If fdate is missing or empty, an actual date string will be generated.

Amplitude values will be written to ASCII files by exptim in floating-point form. digitnum is the number of digits of the mantissas, sent to ASCII files, with the limits 1 digitnum 16, and default value 7.

imptim reads time records from time domain data vectors or files (used by elis). The file may be an ASCII file with comments (usual extension: .tim), a so-called flat ASCII file without comments (.tnt), or a binary file (.tbn). The file has to be somewhere within the path of MATLAB, or the path is to be explicitly given. The default extension is .tbn.

The input argument tdat of imptim is the data vector or the name of the file, or maybe an array of size tlx3, [timevl,xt,yt]; the data vector contains the data in the same order as a *.tnt file.

expi contains the number(s) of the experiment(s) to be read (integer vector). expi is optional; if it is omitted or empty, all the experiments will be read.

Default Argument Values

digitnum = 6,  i = [1:length(xt(:,1))/length(timevect)],
expno = max(i)

Examples

tvect = exptim([1:10],ones(50,1),0.1*ones(50,1),...
     [1:5],5,'data.tbn');
[timevect,xt,yt,expno] = imptim('data.tbn');

Diagnostics

If not experiment No. 1 is being exported to a file, exptim looks for an already existing file. If this is not found, the error message is

File has to exist already when exporting ... . experiment

If a file already exists with the same name, and the first experiment is being exported, exptim tries to delete it. This will be unsuccessful if the file is not in the active subdirectory/folder. In this case the error message is:

Cannot delete existing file ...

imptim checks the validity of the contents of the vector (file). If it is not consistent, an error message is sent:

Not enough data in file ...

or if the read vector is too long, a warning message is displayed:

Number of data is incorrect in file ...