coordinates Data to pixels

uness

I try to get the longitude and latitude of the earth quack on the map but i get a weird values, can someone help me figure out what i'm doing wrong?

I get the following values, which are outside my canvas:

Example of the Json data:

koogs

(when posting code just highlight it and press ctrl-o. you are currently posting it as a quote which is much less readable)

uness

@ Koogs i've edited the code. thanks for the hint

koogs

(it also works for data...)

koogs

 float lan_begin = -13.0; // Longtitude start (largest longitude value)
 float lan_eind = -25.0; // Longtitude end (smallest longitude value)
 float lon_begin = 66.8;  // Latitude start (largest latitude value)
 float lon_eind = 63.1; // Latitude end (smallest latitude value)

...

float x = map(latitude, lan_eind, lan_begin, 0, 1000 );
float y = map(longitude, lon_eind, lon_begin, 0, 800);

lan_begin = longitude start but you're comparing latitude against it when setting x...

uness

with map i try to get the value of the pixel on the canvas using the latitude/longitude i get from the Json file and the latitude and longitude of Iceland.

when i change the lantitude and the longitude to -180,180 and -90,90 i get the following vallues, but there are @ the same arae:

680.0611,324.95554
681.1806,327.1289
681.1806,327.12
681.1778,327.11554
684.72504,322.2311
684.2055,317.2311
676.825,314.88
681.01666,327.8089
681.0417,327.88446
678.87775,322.93335
682.50275,325.46664
677.6639,311.12
677.64996,311.11554
682.51666,325.29333
677.5305,302.17776
676.67773,314.93777
676.79443,313.88446
679.19165,321.72
678.49445,308.87555
683.51385,322.45334
677.0083,296.68
676.67224,295.95554
676.69446,314.9867
677.3444,299.9289
676.8472,296.6489
679.7278,324.52
676.81665,314.71558
676.80835,315.1511
680.0445,324.99557
683.6528,321.48444
679.1861,321.34222
680.03613,324.98666
677.7139,314.03998
677.4055,301.79556
679.71387,322.5422
681.05835,327.66223
676.74164,314.77332
676.80554,314.6667

koogs

did you change these lines?

float x = map(latitude, lan_eind, lan_begin, 0, 1000 );
float y = map(longitude, lon_eind, lon_begin, 0, 800);

because i think they need to be

float x = map(longitude, lan_eind, lan_begin, 0, 1000 );
float y = map(latitude, lon_eind, lon_begin, 0, 800);

(swapping the longitude (east-west) and latitude (north-south))

uness

@ Koogs thank you very much. it works now ;)