PLOT_FIELD Procedure

Standard Library procedure that plots a two-dimensional velocity field.

CAUTION: Extra care must be taken if you run the PLOT_FIELD and VEL procedures in the same PV-WAVE session. Each procedure calls a routine named ARROWS, but the ARROWS routines are slightly different. If you get an error in the ARROWS routine when you are using PLOT_FIELD, recompile PLOT_FIELD (by typing .run PLOT_FIELD), and then try again.

Example

u = FLTARR(21, 21)
v = FLTARR(21, 21)

; Create the arrays.

.RUN

; After you type .RUN, the prompt WAVE will change to a dash (-)
; to indicate that you may enter a complete program unit.

FOR j = 0, 20 DO BEGIN
FOR i = 0, 20 DO BEGIN
x = 0.05 * FLOAT(i)
z = 0.05 * FLOAT(j)
u(i, j) = -SIN(!Pi * x) * COS(!Pi * z)
v(i, j) =  COS(!Pi * x) * SIN(!Pi * z)
ENDFOR
ENDFOR

END

; This procedure puts values into the array. The last END exits you
; from programming mode, compiles and executes the procedure,
; and then returns you to the WAVE prompt.

PLOT_FIELD, u, v, Title = 'Velocity Field'

; Display the velocity field with default values (Figure 2-73).

Figure 2-73 Velocity field displayed with default values.

Figure 2-74 Velocity field displayed with default values.

PLOT_FIELD, u, v, N = 400, Title = 'Velocity Field'

; Display the velocity field using 400 arrows (see Figure 2-75).

Figure 2-75 Velocity field displayed with 400 arrows.

Figure 2-76 Velocity field displayed with 400 arrows.

PLOT_FIELD, u, v, Aspect = .7, Length = .4,$
    N = 20, Title = 'Example of PLOT_FIELD'

; Display the velocity field with individual modifications (shown
; in Figure 2-77).

Figure 2-77 Velocity field modified with various keywords.

Figure 2-78 Velocity field modified with various keywords.

PLOT_FIELD Procedure

Usage

Input Parameters

Keywords

Discussion

Example

See Also