Flot图表勾选问题

Question

I have a flot graphs with a custom tick formatter function,

if ((val / 1000) >= 1) {
    val = String(Math.round(val / 1000)) + 'K';
}

return String(val);

But the issue is it returns same values for some ticks.

Little explanation about code:

val --> any integer value ranging from 1 to infinity

val / 1000 logic is to convert the tick into user friends (readable) format (1K, 2K etc).

But the issue here is I get repeated tick labels when some val round up to equal values.

It want to know any good way to fix this algorithm to calculate this?

Addendum

val / 1000 does not mean val is multiple of 1000 it could be any integer value ranging from 1 to infinity.

Eg: For val = 1000 or 1001 it return 1K on two tick labels.

I know its algorithmic bug .I just wanna to know if there is any way to fix it cleanly

Notes

1. Ticks must be rounding to two decimal at the most (great if no decimal points).
2. You cannot change val / 1000 . You can Play round with Math.round() function.
3. Even if want to use toFixed() follow Rule 1

Answer 1

Here's a solution that uses suffixes for large numbers while keeping the accuracy:

function tick_label(val) {
    if (val < 0) return "\u2212" + tick_label(-val);
    if (val < 1000) return String(val);

    var mag = 1;
    var suffix = "";

    if (val >= 1000) { mag = 1000; suffix = "k" }
    if (val >= 1000000) { mag = 1000000; suffix = "M" }
    if (val >= 1000000000) { mag = 1000000000; suffix = "G" }

    var div = mag;

    while (val % 10 == 0) {
        val /= 10;
        div /= 10;
    }

    return String(val / div) + suffix;
}

This code relies on round numbers for ticks, so that the exact number doesn't look strange or overly exact. (A scale of 1.002k, 1.004k, 1.006k looks okay, but a scale of 1.102k, 1.202k, 1.302k does not. I'm not familiar with Flot, but I guess it takes care of that.)