# TABRND1

Bulk Data Entry Defines power spectral density as a tabular function of frequency for use in random analysis. Referenced on the RANDPS entry.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TABRND1 ID XAXIS YAXIS FLAT
f1 g1 f2 g2 f3 g3 f4 g4

## Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TABRND1 3
2.5 .01057 2.6 .01362 ENDT
etc

## Definitions

Field Contents SI Unit Example
ID Table identification number.

(Integer > 0)

XAXIS Specifies a linear or logarithmic interpolation for the x-axis. 5
LINEAR (Default)
LOG

YAXIS Specifies a linear or logarithmic interpolation for the y-axis. 5
LINEAR (Default)
LOG

FLAT
Specifies the handling method for y-values outside the specified range of x-values in the table.
=0 (Default)
If an x-value input is outside the range of x-values specified on the table, the corresponding y-value look up is performed using linear extrapolation from the two start or two end points.
=FLAT or 1
If an x-value input is outside the range of x-values specified on the table, the corresponding y-value is equal to the start or end points, respectively.

fi Frequency value in cycles per unit time. Must be in either ascending or descending order, but not both.

(Real > 0.0)

gi Power spectral density.

(Real)

1. Jumps between two points $\left({\mathrm{f}}_{i}+{\mathrm{f}}_{i+1}\right)$ are allowed, but not at the end points.
2. At least two entries must be present.
3. Any f-g entry may be ignored by placing the BCD string SKIP in either of the two fields used for that entry.
4. The end of the table is indicated by the existence of the BCD string ENDT in either of the two fields following the last entry. An error is detected if any continuations follow the entry containing the end-of-table flag ENDT.
5. For FLAT=0 (default), TABRND1 mnemonic infers the use of the algorithm:(1)
$G=gT\mathit{\left(}F\mathit{\right)}$
Where,
$F$
Input to the table
$G$
Is returned

The table look-up $gT\left(f\right)$ is performed using linear extrapolation outside the table using the last two end points at the appropriate table end. At jump points, the average $gT\left(F\right)$ is used. There are no error returns from this table look-up procedure.

For FLAT=1, the same algorithm as FLAT=0 is used, except that values outside the range are not extrapolated. The corresponding start or end point y-values are used for all y-values outside the range.