wide_sample.csv

name,x1,x2,1,2,3,4,5,6,7,8,9,10
a,1,0,1,,3,,5,,7,,9,
b,2,0,,4,,8,10,,14,,,20
c,3,0,0.1,0.2,,0.4,,0.6,,0.8,,1
d,4,0,,1,1.5,2,2.5,,,4,,5
e,5,0,3,,9,12,,18,,,,30