2-D Lookup Table
Two-dimensional approximation function.
Description
Block 2-D Lookup Table calculates the approximate value of the function from the known values of the function at the reference points, given the data points , , . The points are identical to and .
The data vectors and must be strictly increasing. The size of the array of tabulated function values must match the dimensionality of the interpolation grid. That is, if the inputs are a vector of 1 at and a vector of 1 at , that is, if the reference points are specified as a vector of dimension at .
The block calculates the output value based on usage of the lookup table and the selected interpolation and extrapolation methods.
You can read more about interpolation and extrapolation methods here: Methods of approximation of function values
The block icon 2-D Lookup Table displays the graph of the function defined in the block.
Ports
Output
#
OUT_1
—
output signal calculated by searching or interpolating from the table of values
scalar | vector | matrix
Details
An output signal calculated by searching or interpolating from a table of values.
| Data types |
|
| Complex numbers support |
Yes |
Input
#
u1
—
function argument on the first dimension (rows)
scalar | vector | matrix
Details
An input signal , matched to an output value by searching or interpolating from a table of values.
| Data types |
|
| Complex numbers support |
Yes |
#
u2
—
function argument on the second dimension (columns)
scalar | vector | matrix
Details
An input signal , matched to an output value by searching or interpolating from a table of values.
| Data types |
|
| Complex numbers support |
Yes |
#
T
—
output table
`value matrix with dimension corresponding to the number of table dimensions and the number of reference points for each table dimension'
Details
Define an output value table with a runtime configurable signal.
During simulation, the size of the matrix must match the number of reference points for each dimension of the table. However, during block diagram editing, you can enter an empty matrix or an undefined workspace variable. This technique allows you to postpone specifying a matrix with the correct dimensions for the table data and continue editing the flowchart.
Dependencies
To use this port, set the parameters to Table data source value Input port.
| Data types |
|
| Complex numbers support |
Yes |
#
bp
—
datums
`Vector of monotonically increasing values of 1 by n or n by 1'
Details
Specify the values of the reference points based on the signal adjusted at runtime.
Dependencies
To use this port, set the parameters to Breakpoints 1 source value Input port.
| Data types |
|
| Complex numbers support |
Yes |
Parameters
Основные
#
Table data —
output value table
Matrix of real and/or complex numbers
Details
Table of output values.
| Default value |
|
| Program usage name |
|
| Tunable |
Yes |
| Evaluatable |
Yes |
#
Table data source —
table data source
Dialog | Input port
Details
The data source for the table specified as:
-
Dialog- table data specified in parameters Table data. -
Input port- table data will be received through the corresponding input port.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Breakpoints 1 —
reference point values for the first measurement (rows)
Array of real numbers
Details
Reference points for the first dimension (rows). Data set presented as a table where values are represented in cells with coordinates (row, column).
The first dimension (rows) anchor points to the values of the rows in this table.
Dependencies
To use this parameter, set parameter Breakpoints 1 source value Dialog.
| Default value |
|
| Program usage name |
|
| Tunable |
Yes |
| Evaluatable |
Yes |
#
Breakpoints 1 source —
data source for datum points from the first measurement
Dialog | Input port
Details
The data source for the first dimension datums (rows) specified as:
-
Dialog- datum data for datum points specified in parameters Breakpoints 1. -
Input port- The reference point data will be received via the corresponding input port.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Breakpoints 2 —
reference point values for the second dimension (columns)
Array of real numbers
Details
Second dimension datum points (columns). A data set presented as a table where values are represented in cells with coordinates (row, column).
Second dimension anchor points (columns) point to the values of the columns in this table.
Dependencies
To use this parameter, set parameter Breakpoints 2 source value Dialog.
| Default value |
|
| Program usage name |
|
| Tunable |
Yes |
| Evaluatable |
Yes |
#
Breakpoints 2 source —
data source for datums in the second dimension
Dialog | Input port
Details
The data source for the reference points in the second dimension, specified as:
-
Dialog- Breakpoints 2 reference point data is specified in the Breakpoints 2 parameters. -
Input port- The reference point data will be received via the corresponding input port.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
Методы аппроксимации
#
Interpolation method —
method of interpolation between the values of reference points
Flat | Nearest | Linear point-slope | Linear Lagrange | Cubic spline
Details
When the input signal falls between the reference point values, the unit interpolates the output value using the neighbouring points.
Read more about interpolation methods here: Methods of approximation of function values
Dependencies
If you select `Cubic spline`then the block will only support scalar signals. Other interpolation methods support non-scalar signals.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Extrapolation method —
a method of processing input values that are outside the range of the dataset of reference points
Clip | Linear | Cubic spline
Details
Choice of extrapolation method.
Read more about extrapolation methods here: Methods of approximation of function values
Dependencies
To choose Cubic spline for Extrapolation method, you must also select Cubic spline for Interpolation method.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |