How can I draw a circle on a graph using point data and the axis?
 

I am working with Mohr circles and I want to draw a circle on my graphs using
a data point (x,y) values to make the circles. Now if I were using a
compass, I would set my compass point on the x-axis at the x-value and then
draw a circle with radius (y) around that point making certain that I
intercept the x-axis at distance (x + y), (x - y) and point (x,y). I am
trying to figure out if there is someway I can conveniently construct these
circles in excel rather than printing out the graph and then hand-drawing
them over the plotted data points.

Answer: How can I draw a circle on a graph using point data and the axis?
 

Yes, you can draw a circle on a graph using point data and the axis in Microsoft Excel. Here are the steps:

1. Enter your data points (x,y) in two separate columns in Excel.
2. Select the data points and click on the "Insert" tab in the ribbon.
3. Click on "Scatter" in the "Charts" section and select the scatter chart type you want to use.
4. Right-click on one of the data points in the chart and select "Add Trendline".
5. In the "Format Trendline" pane, select "Polynomial" as the trendline type.
6. Set the order to "2" and check the "Display Equation on chart" and "Display R-squared value on chart" boxes.
7. Close the pane and right-click on the trendline in the chart.
8. Select "Format Trendline" and go to the "Line Style" tab.
9. Set the line color and width to your preference.
10. Go to the "Marker" tab and select "None" for the marker type.
11. Close the pane and you should see a circle plotted on your chart based on the data points you entered.

Note: The equation displayed on the chart is the equation of the circle in standard form, which you can use to calculate the intercepts and radius of the circle.

How can I draw a circle on a graph using point data and the axis?
 

I haven't done Mohr's Circle since gradual school.... Knowing the (Xc,Yc)
coordinates of the circle's center, and the circle's radius R, you can
calculate points of the circle, then plot the points on the chart: Put Xc,
Yc, and R into B1, C1, and D1.

Enter 0 in A3 and 10 in A4. Select A3:A4, then drag the black square at the
bottom right corner of the selection downward until you have filled from 0
to 360 in steps of 10 (down to A39).

In B3 enter this formula:

=$B$1+$D$1*COS(A3*PI()/180)

In C3 enter this formula

=$C$1+$D$1*SIN(A3*PI()/180)

Select B3:C3, and double click on the little black square on the bottom
right corner of the selection, which will fill these formulas down to row
39. Select & copy B3:C39, select the chart, and use Paste Special to add
this data to the chart as a new series.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
Peltier Technical Services, Inc. - http://PeltierTech.com
_______


"Graphically Challenged" <Graphically
wrote in message ...
I am working with Mohr circles and I want to draw a circle on my graphs
using
a data point (x,y) values to make the circles. Now if I were using a
compass, I would set my compass point on the x-axis at the x-value and
then
draw a circle with radius (y) around that point making certain that I
intercept the x-axis at distance (x + y), (x - y) and point (x,y). I am
trying to figure out if there is someway I can conveniently construct
these
circles in excel rather than printing out the graph and then hand-drawing
them over the plotted data points.