Prime 8.0 How can I plot a circle

[Snowshoe_Bob]

How can I plot a circle in the X-Y plane, only knowing the radius and location of the circle center?

I have Mathcad Prime 8.0.

[Cornel · Accepted solution]

[Snowshoe_Bob]

Thank you!  That was easy.

[Snowshoe_Bob]

One more request.  Is there a way to modify the above where there is a circle intercept at (0,0) ?

Thanks for your help.

[Werner_E]

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@Snowshoe_Bob wrote:

One more request.  Is there a way to modify the above where there is a circle intercept at (0,0) ?

Thanks for your help.

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I am not sure what you mean. If you know the center of the circle and if you demand that (0,0) should be a point of the circles circumference, you sure are able to calculate the circle radius and so can use the very same approach which was shown to you.

Here is a circle function I often use when I have to draw a circle.

You may use it to draw partial circles

to draw regular polygons

or to play around and create mandala like pics

Prime 9 worksheet attached

[Snowshoe_Bob]

Sorry.... I was not clear.  I mean that one point on the circle will be at (0,0) with a center in Quadrant 1 at a point (x,y).

[Werner_E]

Yes, I had already suspected that and therefore suggested calculating the radius (as the distance between the two points, with Pythagoras, r= sqrt(x^2+y^2)) and then using the method already suggested or the function I posted to draw the circle.

[Snowshoe_Bob]

Thank you!  I will try to plug in your equations.  I have Prime 8.0 so I could not use it directly.

[Snowshoe_Bob]

This this bit of programming [NaN NaN} ?  Looks like the first trial bombed.  I am a novice at programming.  See attached.

[ttokoro]

[NaN NaN] makes pen off for the plot line.

[Snowshoe_Bob]

Thanks!!

[Werner_E]

Hope this helps:

BTW, you sure can use 400 points to make the circle but you would be surprised that even much less points make up a quite good representation of a circle as well.

[Snowshoe_Bob]

Thank you!  It works!

Bob

[Snowshoe_Bob]

Werner,

Update:  If I resolve the point as a radius, then compare that radius to the radius of the circle, the problem is solved I believe.

In relationship the above math, is there a boolean or math routine to determine if a X-Y point is inside or outside the circle?  Can suggest a tack to take to solve this problem?

[Werner_E]

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@Snowshoe_Bob wrote:

Werner,

Update:  If I resolve the point as a radius, then compare that radius to the radius of the circle, the problem is solved I believe.

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Which problem?

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In relationship the above math, is there a boolean or math routine to determine if a X-Y point is inside or outside the circle?  Can suggest a tack to take to solve this problem?

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Not sure what the problem is!?  A point is inside the circle if its distance from the circle center is less than the circle radius.

You may use a test function like this:

Playing around ...

Worksheet in Prime 6 format attached

[Snowshoe_Bob]

I like what you did...  I would have handled it a bit more rudimentary.   But your solution is best.

Thanks!

[LucMeekes]

For those limited to express, here is a set of functions to draw shapes:

And you can stack the result to create complex shapes, such as the CE mark:

Success!
Luc

[Snowshoe_Bob]

Thanks!

[Snowshoe_Bob]

This looks very handy!

[ttokoro]

[Werner_E]

Nice, but why only circles parallel to the xy-plane?

[Werner_E]

Playing around with the inscribed circles of the surfaces of a dodecahedron

[Snowshoe_Bob]

Nice!  Thank you.  Will work for future programming..

[Snowshoe_Bob]

Very cool!  Thank you

[ttokoro]

Thanks show us not x-y plane plot. I try it.

[Werner_E]

[ttokoro]

Good eye!

[Snowshoe_Bob]

Thank You!