fraction

pub fn fraction(self: *Axis, val: f64) f32 {
        if (self.min == null or self.max == null) return 0;

        const min = self.min.?;
        const max = self.max.?;

        switch (self.scale) {
            .linear => {
                return @floatCast((val - min) / (max - min));
            },
            .log => |log_data| {
                const val_exp = std.math.log(f64, log_data.base, val);
                const min_exp = std.math.log(f64, log_data.base, min);
                const max_exp = std.math.log(f64, log_data.base, max);
                return @floatCast((val_exp - min_exp) / (max_exp - min_exp));
            },
        }
    }