Sets the sample rate of a uniformly sampled series.
SETRATE(series, Fs)
series |
- |
Optional. A series or table, defaults to the current Window. |
Fs |
- |
A real, the new sample rate. |
col |
- |
Optional. An integer, the column number. Defaults to -1 for all columns. |
setrate(5.0)
sets the current RATE to 5.0, i.e. 5 samples per second or equivalently a DELTAX of 0.2 seconds per sample if the horizontal units are seconds.
a = 1..100;
setrate(a, 3);
sets the RATE of variable a to 3, i.e. 3 samples per second or equivalently a DELTAX of 1/3 seconds per sample if the horizontal units are seconds.
W1: randn(100, 3);setrate(10.0, 2)
W2: col(w1, 1)
W3: col(w1, 2)
W4: col(w1, 3)
W1 contains a 10x3 random array with a default sample rate of 1.0. The rate of the second column is explicitly set to 10.0 samples per second.
W2 contains column 1 of W1 where rate(w2) == 1.
W3 contains column 2 of W1 where rate(w3) == 10.
W4 contains column 3 of W1 where rate(w3) == 1.
By default, SETRATE changes the sample rate of each column of data to the new rate. For example,
ravel({1, 3, 5}, grandom(3, 0.1)); setrate(100)
sets the rate of the generated series in column 1 as well as the generated random series in column 2 to 100.
The RATE of a series is the inverse of the DELTAX:
Many series have X values that are monotonically rising by a constant X increment such that:
A series with X values of this form is referred to as an interval series. Because any X value from an interval series can be computed with:
an interval series requires only the RATE or DELTAX and XOFFSET values to determine the X values. Thus, for an interval series, explicit X values are not necessary, decreasing the data storage requirements by a factor of 2. Also, because the X values for an interval series are regularly monotonic, speed optimizations for plotting and computations are available.
See SETDELTAX to set the DELTAX of a series.
See XY to create a series with irregularly spaced X values.