objective c - iOS-charts with exponential x-axis -

i have requirement plot graph y-axis range (-15 db 15 db).

plot values got float array -e.g

float plotval[] = {         0.707087f,         0.715769f,         0.724338f,......};(contains 560 points) 

my x-axis value should range 20 hz 20,000hz in logarithmic scale shown in image

i using ios-charts , populating values as

nsmutablearray *xvals = [[nsmutablearray alloc] init];     int xcount = 560;      (int = 0; < xcount; i++)     {         [xvals addobject:[@(i) stringvalue]];      }      nsmutablearray *yvals = [[nsmutablearray alloc] init];      int ycount = 560;      (int = 0; < ycount; i++)     {       [yvals addobject:[[chartdataentry alloc] initwithvalue:plotval[i] xindex:i]];      } 

how change scale values shown in image,please help.

currently, ios-charts not support such scenarios. filed request support, needs decent work on it.

the thing try understand how ios-charts draw line chart, , create new chart based on framework. can so.

the hard part is, rewrite xaxis, , figure out how calculated coordinates.

it's long story explain every details, , code can tell everything, try.