# EDITMT: help and advice

Consult the reference manual for further details and worked examples.
W.G.Bardsley, University of Manchester, U.K.

Summary

This program is designed for use with SIMFIT statistics and plotting data tables with n rows and m columns, containing only numerical data and with no missing values or labels. Such data matrices will usually be created as files, either by program MAKMAT, or by transferring data from a spreadsheet using a macro (e.g. simfit6.xls), or using the clipboard and MAKSIM. EDITMT provides many options that only make sense in the context of data matrices, e.g., transposing, or transforming. If the input data are in a data file, then this program will only work in Save As ... mode, so it does not alter the original data file in any way, it simply creates a new edited data set, a feature that will be greatly appreciated by those who have lost precious data sets using editors that provide Save... as well as Save As ... functionality. You can use SIMSTAT to calculate eigenvalues, inverse, SVD, determinants, etc. for the new matrix after editing.

How to use EDTMT

EDITMT reads in vectors or matrices prepared by MAKMAT and lets you edit as follows.

Alter any individual element.
Insert, delete, transform, replace, set-constant, reciprocate, exponentiate, log, logit, sin, cos, tan, arcsin, arcos, arctan, sinh, cosh, tanh, ... etc. any chosen row or column.,
Perform matrix manipulations: swap, add, subtract, multiply, divide, etc. chosen rows or columns.

You can read files into EDITMT and alter individual elements directly from the terminal, but this is not the best way to add new rows or columns of data etc. To edit large matrices, use MAKMAT to prepare files containing any new data, and then use EDITMT to insert these into the current vector or matrix, either to enlarge or over-write the current data set.

EDITMT saves the current vector or matrix in a work-space and it also saves the last row and column deleted during editing, so you can replace, move, insert, replicate, etc. any rows or columns.

You can also copy out a sub-matrix and then write it to file. This can be used to overwrite blocks of the current matrix. Input files are only altered if you choose to overwrite but edited data will always be written to an output file.

Summary of editing functions

- Alter an element or do transformations on one row or column
- Insert/move/replace/replicate a (new/deleted) row vector
- Delete/store a row vector
- Do transformations using two rows simultaneously
- Insert/move/replace/replicate a (new/deleted) column vector
- Delete/store a column vector
- Do transformations using two columns simultaneously
- Edit title/text then create file with/without header/trailer

Summary of matrix manipulations

- Transpose or reflect the matrix top-bottom/left-right
- Insert/over-write a data file into the current matrix
- Write a sub-matrix block to file (e.g. to copy/paste)
- Change the sign of a chosen row/column vector
- Insert/over-write from data file into current vector
- Rearrange vector into increasing/decreasing order.

Advice

Using this program you can do almost any matrix transformation. As an example, suppose you had a matrix containing a column of percentages in column 3 and you wanted to insert a column with the arcsine transforms as column number 7. You would first of all delete column 3, which places the deleted column in store. Then you would insert copies of the deleted column at positions 3 then 7 as new columns. This new column 7 would then be first divided by 100 to create proportions, then the square root of the proportions would be taken and transformed into arcsines. (If you do ANOVA in SIMFIT such variance stabilising transforms are, of course, done automatically ... this is just an example) Row or column vectors in the matrix will either be transformed completely or not at all. For instance, if a value is negative and a log or square root is requested, you will be warned that transformation is impossible and the vector will be unchanged. The program only stores one row and one column for cutting and pasting interactively, but you can write any sub-matrix to a scratch file at any time for pasting. Be careful with degrees and radians and ranges when using trigonometric transforms.