“变量转换”的版本间差异

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(以“==浮点数转成整数== *round:四舍五入 IDL>print,round(5.1),round(5.9) IDL> 5, 6 *ceil:向上进 IDL>print,round(5.1),round(5.9) IDL> 6, 6 *floor:截取...”为内容创建页面)
 
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第4行: 第4行:
IDL> 5, 6
IDL> 5, 6
*ceil:向上进
*ceil:向上进
IDL>print,round(5.1),round(5.9)
IDL>print,ceil(5.1),ceil(5.9)
IDL> 6, 6
IDL> 6, 6
*floor:截取整数
*floor:截取整数
IDL>print,round(5.1),round(5.9)
IDL>print,floor(5.1),floor(5.9)
IDL> 5, 5
IDL> 5, 5


*整数范围很小(long),要转换大的数,加上/L64
*结果是long型的整数要转换大的数,加上/L64
*[[astro_lib]]中的nint程序,可以代替round,而且
*[[astro_lib]]中的nint程序,可以代替round,而且
:*(1) if no absolute value exceeds 32767, then the array is returned as
:(1) if no absolute value exceeds 32767, then the array is returned as a type INTEGER instead of LONG
:(2) NINT will work on strings, e.g. print,nint(['3.4','-0.9']) will give [3,-1], whereas ROUND() gives an error message
as a type INTEGER instead of LONG

:*(2) NINT will work on strings, e.g. print,nint(['3.4','-0.9']) will
==消除变量==
give [3,-1], whereas ROUND() gives an error message
*temporary(var)

2016年6月9日 (四) 10:37的最新版本

浮点数转成整数

  • round:四舍五入
IDL>print,round(5.1),round(5.9)
IDL> 5, 6
  • ceil:向上进
IDL>print,ceil(5.1),ceil(5.9)
IDL> 6, 6
  • floor:截取整数
IDL>print,floor(5.1),floor(5.9)
IDL> 5, 5
  • 结果是long型的整数,要转换更大的数,加上/L64
  • astro_lib中的nint程序,可以代替round,而且
(1) if no absolute value exceeds 32767, then the array is returned as a type INTEGER instead of LONG
(2) NINT will work on strings, e.g. print,nint(['3.4','-0.9']) will give [3,-1], whereas ROUND() gives an error message

消除变量

  • temporary(var)