合理优化图表缩放 [英] Reasonable optimized chart scaling
问题描述
我需要制作具有优化的 y 轴最大值的图表。
我使用图表的当前方法只是使用所有图的最大值，然后将其除以十，并将其用作网格线。我没有写。
更新注意：这些图表已更改。一旦我修复了代码，我的动态图开始工作，使这个问题无意义（因为示例中不再有任何错误）。我已经更新这些与静态图像，但一些答案反映不同的值。记住这一点。
到目前为止，2月份有12003到14003个入站呼叫。
我想避免看起来像猴子的图表出现了 y 轴号码。
使用Google图表API有点帮助，但它仍然不是我想要的。
数字是干净的，但y值的顶部总是与图表上的最大值相同。此图表的范围从0到1357.我需要计算适当的值1400，有问题。
我投入在
我已经用一种粗暴的
强制方法做到了。首先，找出
的最大刻度线数，你可以把
放入空格。将总
值的范围除以
的数量;这是刻度的最小
间距。现在计算
对数底的底数10到
得到tick的幅度，
除以这个值。你应该结束
up，范围为1到
10.只需选择大于或等于该值的循环数，
将它乘以之前计算的对数
。
这是您的
最终点击间距。
import math
def BestTick（maximum，mostticks）：
minimum = largest / mostticks
magnitude = 10 **数学。
残余=最小/幅度
如果残差> 5：
tick = 10 * magnitude
elif residual> 2：
tick = 5 * magnitude
elif residual> 1：
tick = 2 * magnitude
else：
tick = magnitude
return tick
I need to make a chart with an optimized y axis maximum value.
The current method I have of making charts simply uses the maximum value of all the graphs, then divides it by ten, and uses that as grid lines. I didn't write it.
Update Note: These graphs have been changed. As soon as I fixed the code, my dynamic graphs started working, making this question nonsensical (because the examples no longer had any errors in them). I've updated these with static images, but some of the answers refrence different values. Keep that in mind. There were between 12003 and 14003 inbound calls so far in February. Informative, but ugly.
I'd like to avoid charts that look like a monkey came up with the y-axis numbers.
Using the Google charts API helps a little bit, but it's still not quite what I want. The numbers are clean, but the top of the y value is always the same as the maximum value on the chart. This chart scales from 0 to 1357. I need to have calculated the proper value of 1400, problematically.
I'm throwing in rbobby's defanition of a 'nice' number here because it explains it so well.
- A "nice" number is one that has 3 or fewer non-zero digits (eg. 1230000)
- A "nice" number has the same or few non-zero digits than zero digits (eg 1230 is not nice, 1200 is nice)
- The nicest numbers are ones with multiples of 3 zeros (eg. "1,000", "1,000,000")
- The second nicest numbers are onces with multples of 3 zeros plus 2 zeros (eg. "1,500,000", "1,200")
Solution
I found the way to get the results that I want using a modified version of Mark Ransom's idea.
Fist, Mark Ransom's code determines the optimum spacing between ticks, when given the number of ticks. Sometimes this number ends up being more than twice what the highest value on the chart is, depending on how many grid lines you want.
What I'm doing is I'm running Mark's code with 5, 6, 7, 8, 9, and 10 grid lines (ticks) to find which of those is the lowest. With a value of 23, the height of the chart goes to 25, with a grid line at 5, 10, 15, 20, and 25. With a value of 26, the chart's height is 30, with grid lines at 5, 10, 15, 20, 25, and 30. It has the same spacing between grid lines, but there are more of them.
So here's the steps to just-about copy what Excel does to make charts all fancy.
- Temporarily bump up the chart's highest value by about 5% (so that there is always some space between the chart's highest point and the top of the chart area. We want 99.9 to round up to 120)
- Find the optimum grid line placement for 5, 6, 7, 8, 9, and 10 grid lines.
- Pick out the lowest of those numbers. Remember the number of grid lines it took to get that value.
- Now you have the optimum chart height. The lines/bar will never butt up against the top of the chart and you have the optimum number of ticks.
PHP:
function roundUp($maxValue){
$optiMax = $maxValue * 2;
for ($i = 5; $i <= 10; $i++){
$tmpMaxValue = bestTick($maxValue,$i);
if (($optiMax > $tmpMaxValue) and ($tmpMaxValue > ($maxValue + $maxValue * 0.05))){
$optiMax = $tmpMaxValue;
$optiTicks = $i;
}
}
return $optiMax;
}
function bestTick($maxValue, $mostTicks){
$minimum = $maxValue / $mostTicks;
$magnitude = pow(10,floor(log($minimum) / log(10)));
$residual = $minimum / $magnitude;
if ($residual > 5){
$tick = 10 * $magnitude;
} elseif ($residual > 2) {
$tick = 5 * $magnitude;
} elseif ($residual > 1){
$tick = 2 * $magnitude;
} else {
$tick = $magnitude;
}
return ($tick * $mostTicks);
}
Python:
import math
def BestTick(largest, mostticks):
minimum = largest / mostticks
magnitude = 10 ** math.floor(math.log(minimum) / math.log(10))
residual = minimum / magnitude
if residual > 5:
tick = 10 * magnitude
elif residual > 2:
tick = 5 * magnitude
elif residual > 1:
tick = 2 * magnitude
else:
tick = magnitude
return tick
value = int(input(""))
optMax = value * 2
for i in range(5,11):
maxValue = BestTick(value,i) * i
print maxValue
if (optMax > maxValue) and (maxValue > value + (value*.05)):
optMax = maxValue
optTicks = i
print "\nTest Value: " + str(value + (value * .05)) + "\n\nChart Height: " + str(optMax) + " Ticks: " + str(optTicks)
This is from a previous similar question:
Algorithm for "nice" grid line intervals on a graph
I've done this with kind of a brute force method. First, figure out the maximum number of tick marks you can fit into the space. Divide the total range of values by the number of ticks; this is the minimum spacing of the tick. Now calculate the floor of the logarithm base 10 to get the magnitude of the tick, and divide by this value. You should end up with something in the range of 1 to 10. Simply choose the round number greater than or equal to the value and multiply it by the logarithm calculated earlier. This is your final tick spacing.
Example in Python:
import math
def BestTick(largest, mostticks):
minimum = largest / mostticks
magnitude = 10 ** math.floor(math.log(minimum) / math.log(10))
residual = minimum / magnitude
if residual > 5:
tick = 10 * magnitude
elif residual > 2:
tick = 5 * magnitude
elif residual > 1:
tick = 2 * magnitude
else:
tick = magnitude
return tick
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