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Column Chart scale display

January 13 2011 | 2 comments
Categories: Map Elements

Hi, I'm a spanish native speaker so I will try to make myself understood....

I'm having trouble with the "Column Chart Display" -- by that I mean:

"When you symbolize a layer with charts, a chart symbol and a number are placed in the table of contents under the layer’s name. The number next to the chart symbol represents the attribute value for a chart symbol of that size on the map. For example, a value of five means a chart on the map that is the same size as the chart in the table of contents represents 5 data units."

Ok until here I understand, but i need to adjust that number so I can compare it with other "maps charts". I haven't found the way that I can tell ArcGIS i want that 48 point column is 50.000 people, for example... so in every layer I need to compare and can say is 50.000 is the same size in every map.

It must something really easy to be done.. but I haven't found the way to do it...

Question: how does ArcGIS calculate the "Column Chart Display number"?

Thanks - hope to hear news from you.

Mapping Center Answer:

We wrote a blog entry about the chart legends -- look here for more details: Bar Chart Legends

The answer to your question is that the number next to the chart symbol in the legend relates to the value that the longest bar in the chart represents.

You cannot do much to alter the appearance of a bar chart legend, so you will have to convert it to graphics if you want to make the changes you described. Here is the online help topic for converting the legend (ands other map elements) to graphics (scroll down a bit on the page to see the section titled "Converting map elements to graphics").

But... posted by rocio caces on Jan 14 2011 7:26AM
I get that, i knew that i can convert a graphic and rescale.. but that doesnt work in the map...

I got a layer of 1998 and a layer of 2004 with the same kind of data, and i want to compare the maps so the chart must be in the same scale so they can be comparable..
but in 1998 y get 43,000 and in 2004 55,000 with the same high of chart... how can i make the both 55,000 with the same high column not using the chart in the maps as graphics.

do i make myself clear? any way thaks for tryin but as i told you im no english native speaker
Set the maximum size of the bar posted by Aileen Buckley on Jan 14 2011 10:48AM
I think I understand now what you are trying to do. I think what you need to do is set the maximum length for the bar such that the one for 1998 (43,000) is proportional to the one for 2004 (55,000). 55,000 is 1.279 times bigger than 43,000. So if the maximum length for the 1998 bar is set to 48 pts., set the maximum length for the 2004 bar to 61.39 pts.

To make the math easier, use sizes that are easy fractions of your full values. In the example, drop the thousands and make the 1998 bar maximum height 43 and the 2004 bar maximum height 55 pts.

Attached is an example of what the user interface would look like.

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