var chart = c3.generate({
data: {
columns: [
['data1', 100, 200, 1000, 900, 500]
]
},
grid: {
x: {
lines: [{value: 2}, {value: 4, class: 'grid4', text: 'LABEL 4'}]
y: {
lines: [{value: 500}, {value: 800, class: 'grid800', text: 'LABEL 800'}]
}
});