IDL8

相对于IDL7.1的IDL8系列的新功能

系统变量

• !const

常用物理常数

• biginteger

任意位数的整数

画图

• errorplot

完整的误差棒程序

• barplot

棒状图

• boxplot
• polarplot

极坐标

• vector

画矢量图（箭头）

• streamline
• symbol

画符号，支持latex

• save

可以直接把图保存成文件

p = OBJARR(3)
; Create three plots with random data
FOR i = 0, 2 DO BEGIN
  t = 0.1*FINDGEN(50)
  y = SMOOTH(RANDOMU(seed,50), 5)
  p[i] = PLOT(t,y,'b', SYMBOL='D', TITLE='Observation'+STRING(i+1))
ENDFOR
; Build the multi-page PDF file, one page at a time
p[0].Save, 'data1.pdf', /APPEND
p[1].Save, 'data1.pdf', /APPEND
p[2].Save, 'data1.pdf', /APPEND, /CLOSE

• legend

a = findgen(11)
b = 20./(a+1)^2
p1 = PLOT(a, b, '4', /HISTOGRAM, NAME='Theoretical',  /YLOG, YRANGE=[0.01,100])
p2 = PLOT(RANDOMU(-1, 11), '4r', NAME='Experimental', TRANSPARENCY=50, /HISTOGRAM, /OVERPLOT)
h = LEGEND(POSITION=[9,50], /DATA)

• 画多个panel的时候可以用layout关键词,而且可以动态调整

fn = exp(SIN(FINDGEN(100))^FINDGEN(100))
w1 = WINDOW()
p1 = PLOT(fn, LAYOUT = [1, 2, 1], /CURRENT, TITLE = '1')
p2 = PLOT(fn, LAYOUT = [2, 2, 3], xrange=[25, 42], /CURRENT, TITLE = '2')
p3 = PLOT(fn, LAYOUT = [2, 2, 4], xrange=[50, 60], /CURRENT, TITLE = '3')

• colorbar 用法更自由，target关键词，不需要自己设计
• 直接支持latex符号，text函数
• AXES可以直接在image上画坐标轴

地图相关

• map (可以投影天球)

mymap = MAP('hammer', FILL_COLOR="light_blue")
; Convert from longitude/latitude to meters
longitudes = [-83.02, 88.50]
latitudes = [42.42, 47.17]
xy = mymap.MapForward(longitudes, latitudes)
; Convert back to longitude/latitude and plot
EXPAND, xy, 2, 20, xycoordinates
lonlat = mymap.MapInverse(xycoordinates)
p = PLOT(lonlat[0,*], lonlat[1,*], 'rS',   /OVERPLOT, /SYM_FILLED)

数组运算

• array_equal