c# - Make big and small numbers human-readable -

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• formatting large numbers .net 5 answers

i print small numbers in c# in human friendly way, such as:

30µ 3e-5 or 456.789n 0.000000456789.

i know of humanize_number() function bsd in c, compatible bit ints, not floats , doubles. there equivalent in c# supports those?

also, should keep amount of precision when displaying numbers, like:

0.003596 should displayed 3.596µ, not 3.6µ (or worse, 4µ).

the possible answer here: formatting large numbers .net adapted negative log10 truncating numbers 1 digit after comma. that's far complete in opinion.

examples of how i'd present things:

3000        3k 3300        3.3k 3333        3.333k 30000       30k 300000      300k 3000000     3m 3000003     3.000003m // or 3m if specify "4 digits precision" 0.253       253m 0.0253      25.3m 0.00253     2.53m -0.253003   -253.003m 

i couldn't formulate question find relevant answers in so, if question has been answered, fire away!

try this:

static class extensions {     static string[] prefixes= { "f", "a", "p", "n", "μ", "m", string.empty, "k", "m", "g", "t", "p", "e" };      public static string nice(this double x, int significant_digits)     {         //check special numbers , non-numbers         if(double.isinfinity(x)||double.isnan(x)||x==0||significant_digits<=0)         {             return x.tostring();         }         // extract sign deal positive numbers         int sign=math.sign(x);         x=math.abs(x);         // scientific exponent, 10^3, 10^6, ...         int sci= x==0? 0 : (int)math.floor(math.log(x, 10)/3)*3;         // scale number exponent found         x=x*math.pow(10, -sci);         // find number of digits left of decimal         int dg= x==0? 0 : (int)math.floor(math.log(x, 10))+1;         // adjust decimals display         int decimals=math.min(significant_digits-dg, 15);         // format decimals         string fmt=new string('0', decimals);         if(sci==0)         {             //no exponent             return string.format("{0}{1:0."+fmt+"}",                 sign<0?"-":string.empty,                 math.round(x, decimals));         }         // find index prefix. every 3 of sci new index         int index=sci/3+6;         if(index>=0&&index<prefixes.length)         {             // prefix             return string.format("{0}{1:0."+fmt+"}{2}",                 sign<0?"-":string.empty,                 math.round(x, decimals),                 prefixes[index]);         }         // 10^exp format         return string.format("{0}{1:0."+fmt+"}·10^{2}",             sign<0?"-":string.empty,             math.round(x, decimals),             sci);     }      // test code     static void main(string[] args)     {         double x=math.pi/10e20;                 {             console.writeline(string.format( "\t{0,20} = {1}", x, x.nice(4)));             x*=10;         } while(x<=math.pi*10e20);     } } 

test output 4 significant digits:

    3.14159265358979e-19 = 314.2·10^-2      1.5707963267949e-18 = 1.571f     7.85398163397448e-18 = 7.854f     3.92699081698724e-17 = 39.27f     1.96349540849362e-16 = 196.3f      9.8174770424681e-16 = 981.7f     4.90873852123405e-15 = 4.909a     2.45436926061703e-14 = 24.54a     1.22718463030851e-13 = 122.7a     6.13592315154256e-13 = 613.6a     3.06796157577128e-12 = 3.068p     1.53398078788564e-11 = 15.34p      7.6699039394282e-11 = 76.70p      3.8349519697141e-10 = 383.5p     1.91747598485705e-09 = 1.917n     9.58737992428526e-09 = 9.587n     4.79368996214263e-08 = 47.94n     2.39684498107131e-07 = 239.7n     1.19842249053566e-06 = 1.198µ     5.99211245267829e-06 = 5.992µ     2.99605622633914e-05 = 29.96µ     0.000149802811316957 = 149.8µ     0.000749014056584786 = 749.0µ      0.00374507028292393 = 3.745m       0.0187253514146196 = 18.73m       0.0936267570730982 = 93.63m        0.468133785365491 = 468.1m         2.34066892682745 = 2.341         11.7033446341373 = 11.70         58.5167231706864 = 58.52         292.583615853432 = 292.6         1462.91807926716 = 1.463k          7314.5903963358 = 7.315k          36572.951981679 = 36.57k         182864.759908395 = 182.9k         914323.799541975 = 914.3k         4571618.99770987 = 4.572m         22858094.9885494 = 22.86m         114290474.942747 = 114.3m         571452374.713734 = 571.5m         2857261873.56867 = 2.857g         14286309367.8434 = 14.29g         71431546839.2168 = 71.43g         357157734196.084 = 357.2g         1785788670980.42 = 1.786t          8928943354902.1 = 8.929t         44644716774510.5 = 44.64t          223223583872552 = 223.2t     1.11611791936276e+15 = 1.116p     5.58058959681381e+15 = 5.581p     2.79029479840691e+16 = 27.90p     1.39514739920345e+17 = 139.5p     6.97573699601726e+17 = 697.6p     3.48786849800863e+18 = 3.488e     1.74393424900432e+19 = 17.44e     8.71967124502158e+19 = 87.20e     4.35983562251079e+20 = 436.0e      2.1799178112554e+21 = 2.180·10^21