PLOT Subcommand (SPECTRA command)

PLOT Subcommand (SPECTRA command)

PLOT specifies which plots are displayed. periodogram,periodogram,periodogram SPECTRA command,SPECTRA command,SPECTRA command • If PLOT is not specified, only the periodogram is plotted for each specified series. Each periodogram is shown both by frequency and by period. • You can specify more than one plot keyword. • Keywords can be specified in any order. • The plot keywords K, CS, QS, PH, A, and G apply only to bivariate analyses. If the subcommand CROSS is not specified, these keywords are ignored. • The period (horizontal) axis on a plot by period (BY PERIOD) is scaled in natural logarithms from 0.69 to ln(n), where n is the number of cases. • The frequency (horizontal) axis on a plot by frequency (BY FREQ) is scaled from 0 to 0.5, expressing the frequency as a fraction of the length of the series. • The periodogram and estimated spectrum (vertical axis) are scaled in natural logs. The following plot keywords are available: P Periodogram. This setting is the default. S Spectral density estimate. K Squared coherency. Applies only to bivariate analyses. CS Cospectral density estimate. Applies only to bivariate analyses. QS Quadrature spectrum estimate. Applies only to bivariate analyses. PH Phase spectrum. Applies only to bivariate analyses. A Cross amplitude. Applies only to bivariate analyses. G Gain. Applies only to bivariate analyses. ALL All plots. For bivariate analyses, this setting includes all plots listed above. For univariate analyses, this setting includes the periodogram and the spectral density estimate. reference:tutorial spss