Transform Data Formats

Transform can read in several data formats. Once read in Transform converts the data to a mesh, with no coordinates attached to each point. Transform calls this mesh a Matrix. You may specify the number of rows and columns of the matrix. Transform interpolates the data to fit the mesh. You may choose the interpolation methos.

Transform works best when your data is "rectangular". That is, the data has a rectangular boundary. This is not a requirement, but you will always see a rectangular region when the data is displayed. Each point in the region will have some value. You may choose the value for the "undefined" points.

Transform can read many data formats, including the following

2D HDF
Binary Matrix
Text Matrix
Binary Columns
Text Columns
Text Matrix with row and column labels

Transform can also read in images to display along with your data.

2D HDF

Two dimensional Hierarchical Data Format (HDF) is the easiest to read in. All you have to do is open the file, "Transform" does the rest.

Binary Matrix

The Binary Matrix format is binary data values stored in a two dimensional array. No coordinates are stored with the data. From a FORTRAN program this array is written to a file using an unformated write statement. Binary Data produced by a FORTRAN program causes some minor problems for "Transform". An unformated write statement in FORTRAN will write the data in binary form to a file and will write some additional information. You must tell Transform to ignore this additional information.

From a C program, this array is written to a file by using an fwrite statement.

When you read in binary matrix data, you will see the following

You must choose the number type and then tell "Transform" the number of bytes to ignore at the beginning of the file. If you binary data was produced by a C program, the skip bytes probably will be 0. For FORTRAN, unless other data was written to the file, the skip bytes will probably be 4.

You also need to enter the number of rows and columns, and then click "OK"

Text Matrix

The Text Matrix format is ascii data values stored in a two-dimensional array. No coordinates are stored with the data. To read in data stored as a text matrix, you need to enter the number of rows and columns. You must also enter the number of header lines in the file.

Text Column

The text column data format stores coordinates with the data values. Transform can read in column formats, but it immediately converts it to the matrix format. For more information about this format, see Getting Started .

Binary Column

Binary Column data is similar to text column, except that the data is stored in binary. When you tell "Transform" that the data is binary column data, a window will pop up allowing you to select the number type, the number of rows and the number of columns, and the number of bytes to ignore at the beginning of the data file. The number of columns is the number of values per data point. This at least three: an x-coordinate, a y-coordinate and at least one value.

Text Matrix with row and column labels

Another data format is a text matrix with row and column labels stored with the data. "Transform" calls this data type "Transform ASCII Special". Here is an example data file with this format.

3 4
1.0 10.0
10.0 20.0 30.0
100.0 200.0 300.0 400.0
1.1 1.2 1.3 1.4
2.1 2.2 2.3 2.4
3.1 3.2 3.3 3.4

The first line contains the number of rows and columns. The second line contains the minimum and maximum of the data. If the min and max are both set to zero, then "Transform" will compute the min and max for you.

The next line contains the labels for the rows. After that comes the labels for the columns. The data values are last. All the data for row 1 appears before the data for row 2 and so on.

This information is available in alternative formats upon request by individuals with disabilities. Please send email to alt-format@msi.umn.edu or call 612-624-0528.

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This page last modified on Wednesday, 23-Apr-2008 11:10:38 CDT
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