PLOT produces a simple XY plot.

PLOT_IO produces an XY plot with logarithmic scaling on the y-axis.

PLOT_OI produces an XY plot with logarithmic scaling on the x-axis.

PLOT_OO produces an XY plot with logarithmic scaling on both the x- and y-axes.

; Create a sine wave from 0 to 360 degrees.

x = FINDGEN(37) * 10

y = SIN(x * !Dtor)

; Plot the sine wave using default values for plotting keywords.

PLOT, y

WAIT, 1

; Plot the sine wave against the x values, change the range of

; the x-axis, and add labels. Notice that PV-WAVE rounds the

; requested range values on the axis to values that give a nice

; looking plot, in this case 0 to 400.

PLOT, x, y, XRange=[0, 360], Title='SIN(X)',$

   XTitle='degrees', YTitle='sin(x)'

WAIT, 1

; Use keywords to get the desired style and to add fonts to

; the labels.

PLOT, x, y, XRange=[0, 360], XStyle=1, XTicks=6, $

   XMinor=6, XTitle='!8degrees', YTitle='!8sin(x)!3', $

   Title='!17SIN(X)'

WAIT, 1

; Plot a base line at 0.

PLOTS, [0, 360], [0, 0]

; Set up a predefined color table called tek_color.

TEK_COLOR 

WAIT, 1

; Fill under the positive half of the curve with solid magenta.

POLYFILL, x(0:18), y(0:18), Color=WoColorConvert(6)

WAIT, 1

; Calculate the cosine of x.

z = COS(x * !Dtor)

; Plot cosine using a thick, dashed line and a different color.

OPLOT, x, z, Linestyle=2, Color=WoColorConvert(3), Thick=4

; Create the data.

x = [100, 5000, 20000, 50000, 70000L]

y = [100, 10000, 1100000L, 100000L, 200000L]

; Plot the data on a log-log plot, with dotted grid lines.

; Use a format of I7 for the plot labels.

PLOT_OO, x, y, Ticklen=0.5, Gridstyle=1, $

   Tickformat='(I7)', Title='TEST PLOT', $

   YRange=[1.e2, 1.e7], YStyle=1

; Get the maximum value of y.

max_y = MAX(y)

; Get the value for x when y is at its maximum.

x_max_y = x(WHERE(y EQ max_y))

; Print Test Max centered at the maximum point.

XYOUTS, x_max_y(0), max_y+1.e5, 'Test Max', Alignment=0.5

; Generate the abscissas.

x = FINDGEN(101)/5 + 1

; Generate the function values.

y = 1000 * SIN(1/x^2) + COS(10 * x)

; Initialize the IMSL Mathematics Toolkit

math_init

; Compute the cubic spline interpolant.

pp = CSINTERP(x, y)

; Compute the spline values.

ppval = SPVALUE(FINDGEN(1001)/50 + 1, pp)

; Plot the result with logarithmic scaling on the y-axis.

PLOT_IO, FINDGEN(1001)/50 + 1, ppval

Figure 13-3: Plot of Cubic Spline Interpolant Function using PLOT_IO

; Generate the abscissas and function values.

x = FINDGEN(100) * 10

y = x + 100 * COS(0.05 * x)

; Initialize the IMSL Mathematics Toolkit

math_init

; Compute the cubic spline interpolant.

pp = CSINTERP(x, y)

; Compute the spline values.

ppval = SPVALUE(FINDGEN(1000), pp)

; Plot the result with logarithmic scaling on the x-axis.

PLOT_OI, FINDGEN(1000), ppval, XRange=[10, 1000]

Figure 13-4: Semi-logarithmic Scaling of f(x) using PLOT_OI

; Create the data.

theta = (FINDGEN(200)/100) * !Pi

r = 2 * SIN(4 * theta)

; Display a polar plot, disabling the box-style axes.

PLOT, r, theta, /Polar, XStyle=4, YStyle=4, $

   Title='POLAR PLOT TEST'

; Draw an x-axis at the point 0, 0 with tick marks going down.

AXIS, 0, 0, XAxis=0

; Draw a y-axis at the point 0, 0 with tick marks going left.

AXIS, 0, 0, YAxis=0

temperature = [50., 40., 35., 60., 40.]

pressure = [1025, 1020, 1015, 1026, 1022]

TEK_COLOR

; Plot temperature against scale on the left axis.

PLOT, temperature, YRange=[20., 70], $

   YTitle='Degrees Fahrenheit', XTitle='Sample Number', $

   Title='Sample Data', XMargin=[8, 8], YStyle=8, $

   Color=WoColorConvert(16)

; Create the axis for air pressure.

AXIS, YAxis=1, YRange=[1000, 1040], YStyle=1, $

   YTitle='Air Pressure', /Save, Color=WoColorConvert(6)

; Plot air pressure against scale on the right axis.

OPLOT, pressure, Linestyle=2, Color=WoColorConvert(6)

; Display a legend.

LEGEND, ['Temperature', 'Air Pressure'], $

   WoColorConvert([16, 6]), [0, 2], [0, 0], 2.4, 1005, 2

; Create a date-time array with the first day of 2002.

x = VAR_TO_DT(2002,1,1)

; Create an array of date lines with one value for each month.

x = DTGEN(x, 12, /Month)

; Create an array of data values ranging from 0 to 1000.

y = RANDOMU(seed, 12) * 1000

; Print the current names for months, and then save them.

PRINT, !Month_Names

hold_month_names = !Month_Names

; Change the names to be 3-letter abbreviations for the months.

FOR i=0L, 11 DO !Month_Names(i) = STRMID(!Month_Names(i), 0, 3)

; Create labels on the y-axis that start with a '$'.

ylabels = STRARR(6)

FOR i=0L, 5 DO ylabels(i) = '$' + STRTRIM(string(100L * i * 2), 2)

; Plot the data and restore !Month_names to the original.

PLOT, x, y, /Month_Abbr, /Box, Title='Test Date Plot', $

   YRange=[0, 1000], YStyle=1, YTickname=ylabels, YTicks=5,$

   YTitle='In thousands', YGridstyle=1, YTicklen=0.5

!Month_Names = hold_month_names

; Create some data

TEK_COLOR

n = 9

x = RANDOMU(s,n)*100

y = RANDOMU(s,n)*100

i = SORT(x)

x = x(i)

y = y(i)

; Establish the coordinate system

PLOT, x, y, Thick=2, Psym=10, Xstyle=1, /Nodata

; Calculate the additional x-values

xnew = (x(0:n-2) + x(1:n-1)) / 2.0D

; Create array containing all x-values

xx = REBIN(xnew, N_ELEMENTS(xnew)*2, /sample)

xx = [!X.Crange(0), !X.Crange(0), xx, !X.Crange(1), $

   !X.Crange(1)]

; Create array with the corresponding y-values

yy = REBIN(y, N_ELEMENTS(y)*2, /Sample)

yy = [0, yy, 0]

; Fill the histogram plot

POLYFILL, xx, yy, Psym=2, Color=WoColorConvert(24)

; Histogram plot

PLOT, x, y, Thick=2, Psym=10, Xstyle=1, /Noerase