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## Easy Java Simulations (2001- ) => misc => Topic started by: Fred Chuit on July 23, 2008, 01:39:08 am

 Title: in ejs how to show to number as a power of 10? Post by: Fred Chuit on July 23, 2008, 01:39:08 am Dear Sir,I am just starting to build applets with ejs, it's a wonderful program.I would like some numbers (double) to be shown on screen as a power of 10.For instance: 23000 as: 2,3•10^4  (if possible 4 as exponent)0,00356 as: 3,6•10^-3 (-3 as exponent).Further, is there a way to have a numberfield also accept(and show) the "," instead of the"."?So: 34,5 instead of 34.5It would be great if I could get some simple examples to solve this problems.Already many thanks for the help.Greetings,Fred Title: Re: in ejs how to show to number as a power of 10? Post by: Fu-Kwun Hwang on July 23, 2008, 01:37:22 pm This is what I will do: define a function to convert your value to a string.For example: define variables in the model e (double): 1.602e-19s (String): d2s(v)    // to be used to show e as a String public String d2s(double v){ double a; int b; String o; b=(int)(Math.log(v)/Math.log(10.)); // get the value as power of 10 if(b<0)b=b-1; a=d2v(v/Math.pow(10,b));  o=a+""; return o.replace(".",",")+"*10^{"+b+"}";  // convert "." to ","}public double d2v(double v){//  for 3 digits displayed max. double dv; if(v>0)dv=0.5; else if(v<0)dv=-0.5; else dv=0; return (int)(v*1000+dv)/1000.;}Add a Text element into DrawingPanel, and set it's text to %s%You should be able to find 1.602*10-19 in the drawingPanel when you run it.EJS support (^ or _) for  (superscript or subscript) . Try it at title for PlotingPanel, text element. etc.I also found "." will be switch to "," for value displayed in slider/Bar/...  when you switch locale from en_EN to es_ES. (I think it will work the same if you select the right locale before running EJS). Title: Re: in ejs how to show to number as a power of 10? Post by: Fred Chuit on July 23, 2008, 03:18:56 pm Dear mr. Fu-Kwun Hwang,Many thanks for you advice and help!This really solves the problem, I couldn't fix.Again, thanks for your fast reply!Greetings from Holland,Fred