Save the data to SD as a long or unsigned long by multiplying the number by 1,000,000 before saving. Uses the same 4 bytes but you don't have the inaccuracy of floats. Divide by 1,000,000 and cast as float when you retrieve the number.
I was just trying this, and it works, but the data is a CSV with 1000 waypoint.
they need to read from the SD card and put in 5 array's.
The CSV is output from a datalogger, so we need to do some editing...
On the racetrack while racing , not so handy
If the data was allway's the same format I could use two times a parseInt()
The parseInt() takes the decimal point as terminator...
Working on this solution now, thanks for the advice :-)