Point on chart doesn't match value in the cell it comes from

[ClearConcept]

One point on a simple line chart does not match the value in the cell it comes from. If I hover over any other point & look at the value of the cell, they all match - only one is seemingly arbitrary - and it really stands out, since it shows a much higher value than it shouldCapture.JPG

[MrShorty]

Based on the given picture, about all I can do is agree that the point in question does seem "inconsistent" with the other points in the graph. I'm not sure we will be much help in debugging this without the spreadsheet.

Often when I debug something like this, I will, first, clear all number formats from the cells in question. Sometimes, number formats can "obscure" the actual value in the cell. This step allows me to make absolutely certain that I know what value is in the cell, and, therefore, what value the chart should be charting.

Another thing I will often do is "zoom in" (adjust axis limits) until I can see the data point in question well enough to make a positive ID on that point. The "noise" in your picture suggests that there are a lot of data points used to create this chart. In many (most?) cases where I see this, it ends up being some kind of "data entry" error (entered 105.3 instead of 10.53 type mistake).

I find that Excel's chart engine is pretty accurate. If the chart shows a "spike" like this, then that is somehow present in the data as well. Clearly, the spike is the largest value within the window of your picture. You might try the =MAX() function on that window to see what it returns. You could then feed the result of that MAX() function into a =MATCH() or other lookup function to find the corresponding data point.

Debugging this sort of thing can be tedious. We will not be much help based solely on the picture you provide, but perhaps you can use these strategies to help find the problem data point.

[ClearConcept]

The chart, as you submit, does contain a lot of data points; almost 1600, as a matter of fact.
The value in the cell is a formula: =+C1041+E1041. The chart depicts amounts at specific dates.
I just realized that if I hover over the high point, it shows that erroneous amount on that date, but if I hover over the bottom of that same line, it shows the correct amount for the same date. It actually shows 2 different amounts for the same date.
I have not uploaded the file since it does contain sensitive & personal data...

When I create another chart, using less data, the spike does not result. This is about 100 data points (instead of 1600)
Capture2.JPG

[MrShorty]

Without a spreadsheet, I don't know that I can really be much help. All I can think to do is to encourage you to continue tracing back through the "dependency tree" until you find the error. What is in C1041 and E1041 when the error occurs? Are these values correct, or at least reasonable for the calculation being performed? If these are also formulas, what are the values feeding into those formulas? And continue tracing back through the spreadsheet until you find the error.

Because you can create a chart with another data set that does not exhibit the erroneous behavior, I expect that there is an error somewhere in the raw data for the original data set that is causing these cells to calculate incorrectly.