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function-table

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Library

Signal\Block Diagram Non-Linear

Use

Domains: Continuous. Size: 1-D. Kind: Block Diagrams.

Description

This model uses a one-dimensional table with data points to calculate the output y = f(x) as a function of the input x. The output y is calculated using linear interpolation between the table data points.

The input data of the first column needs to be monotonically increasing.
Discontinuities are allowed, by providing the same input point twice in the table.
Values outside of the table range, are computed by linear extrapolation of the last two points.

table

 

-2.5

-2

0

1

2

3

5

6

 

 

-0.5

-1

-1

0

2

3.0

4

4.0

table

 

A table must be stored either as an ASCII (text) file or as a matrix inside the equation model. In both cases the table should consist two columns of data. The first column consists of the x-values and the second column of the corresponding y-values.

Reading data from a file

If the table is read from a file, each line of the file may only contain one x- and one corresponding y-value. The two values must be separated by a space or a tab. Each new set of x- and y-values must start on a new line. No comment or other text may be part of the table-file. The filename of the input file can be specified using the complete path (e.g. C:\data\data.tbl). When no path is given, the file is assumed to be in the experiment directory.

Interface

Inputs

Description

input

 

Outputs

 

output

 

Parameters

 

filename

The filename of the table file.

Reading data from a matrix

If the table is read from a matrix in an equation model, each row may only contain one x- and one corresponding y-value. The two values must be separated by a coma and each column must be separated by a semi-colon.

Note

Table interpolation can also be used directly in an equation model by using the function table.