这里有一些关于此的主题(使用javascript,c ++等),但尚未找到适合gnuplot的主题.
There are several topics here about this (in javascript, c++,...), but haven't yet found one for gnuplot.
基本上,我想在标签中将"nan"替换为"---".
Basically, I want to replace "nan" with "---" in labels.
我知道我可以设置 NaN ="---" ,但是 NaN 的行为就像一个字符串,需要修改其他代码.
I know that I can set NaN = "---" but then NaN behaves like a string and other code needs to be adapted.
### How to compare to NaN? NaN = GPVAL_NaN # default value for NaN a = NaN print (a==NaN ? "---" : sprintf("%g",a)) print (a==NaN ? sprintf("%g",a) : "---") print (a!=NaN ? "---" : sprintf("%g",a)) print (a!=NaN ? sprintf("%g",a) : "---") a = 123 print (a==NaN ? "---" : sprintf("%g",a)) print (a==NaN ? sprintf("%g",a) : "---") print (a!=NaN ? "---" : sprintf("%g",a)) print (a!=NaN ? sprintf("%g",a) : "---") ### end of code结果:
NaN --- NaN --- 123 --- 123 ---因此,没有一种组合可以完成这项工作.
So, none of the combination does the job.
最后,我发现以下内容似乎可行.
Finally, I found that the following seems to work.
print (a/a == 1 ? sprintf("%g",a) : "---")我的问题:
a/a 是否总是精确地为 1 ,或者在特殊情况下是否可能存在舍入错误?是这样做的方式"还是我忽略了任何事情?
Will a/a always be exactly 1 or could there potentially be rounding errors in special cases? Is this "the" way how to do it or did I overlook anything?
推荐答案只是为了不让这个问题出现而没有答案...
just for the sake of not letting this question appearing unanswered...
一种比较变量 a 是否为 NaN (至少在gnuplot中)(并至少对其进行处理)的最简单方法:
Probably, the easiest way to compare if a variable a is NaN or not (at least in gnuplot) and do something with it:
print (a == a ? sprintf("%g",a) : "---")在SO上对某些编程语言进行讨论之后,人们开始辩论 NaN == NaN 或 NaN!= NaN 或两者都不是.
Following some discussions on some programming languages here on SO, people are debating about NaN==NaN or NaN!=NaN or neither of them.
如果与数据中的字符串"NaN" 进行比较,请参见上面的@Christoph注释.
And in case of comparison to the string "NaN" in data: see @Christoph's comment above.
更多推荐
gnuplot:如何与NaN进行比较?
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