Math Is Fun Forum

nha

Member

Registered: 2010-09-05

Posts: 43

convert from spherical coordinates

Hey all, I really need some help on this one, I just can seem to find a connection anywhere between formulas for each coordinate system.

Convert

from spherical coordinates in to both cartesian coordinates and cylindrical coordinates.

Can anyone help me at all?

Thanks again.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert from spherical coordinates

You want to convert spherical to cartesian and cylindrical?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

nha

Member

Registered: 2010-09-05

Posts: 43

Re: convert from spherical coordinates

You want to convert spherical to cartesian and cylindrical?

Yes, but with it just being phi I am having some trouble.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert from spherical coordinates

I do not see what you can do other than:

For spherical to cartesian:

Just plug in

The rest you just leave as they are.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

nha

Member

Registered: 2010-09-05

Posts: 43

Re: convert from spherical coordinates

This is my attempt to convert to Cartesian.
The polar coordinates of

are

. Using

and

to get

for the Cartesian coordinates, but I am unsure if this is correct. And I still can't seem to get an answer for the cylindrical coordinates.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert from spherical coordinates

Hi;

You have lost me! How can we assume if we have one term in one system that we can get all three in another?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

nha

Member

Registered: 2010-09-05

Posts: 43

Re: convert from spherical coordinates

Hi;

You have lost me! How can we assume if we have one term in one system that we can get all three in another?

Yeah that makes sense but I don't see anything wrong with my working. I think it may be wrong but I can't see the error. It should be in the form (x,y,z), so I think the way you did it here is correct:

For spherical to cartesian:

Just plug in

The rest you just leave as they are.

What about cylindrical coordinates? Do I use:

Last edited by nha (2010-10-10 11:21:43)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert from spherical coordinates

You can help me then. You have solved the simultaneous equations correctly.

How did you get ( 1 , π / 6 )?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

nha

Member

Registered: 2010-09-05

Posts: 43

Re: convert from spherical coordinates

You can help me then. You have solved the simultaneous equations correctly.

How did you get ( 1 , π / 6 )?

Spherical coordinates refer to an angle inscribed on a circle of unit length don't they, so in polar it would be (1, pi/6)? Or is this totally wrong?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert from spherical coordinates

Hi nha;

I do not think that is true about a circle of unit length. You are restricting rho to 1, I have seen it restricted to >0 but not just to 1.

I might be wrong? Please check out these pages and see what you make out of them. Thanks

http://www.math.montana.edu/frankw/ccp/ … /learn.htm

http://en.wikipedia.org/wiki/Spherical_ … ate_system

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.