Talk:Cardioid

From Math Images

Xingda's Comments

Reword the very first description

Make sure it's totally clear where the light source must be positioned in order to generate a cardoid.

Trace of a point?

Change to the path of a point?

Derive the equations for a cardioid, otherwise I'll skim over them.

Generating a Cardioid Using Other Shapes section

You need a more consistent organization for this section. Some of the parts have equations and some don't, and I think you should be consistent. Also, if you don't want to derive these equation too, at least make a note so that someone else can in the future.

Make sure that you can create the diagram based on your description of it. That way, you can be sure that you're not confusing anyone.

Make the caustic part more clear. I think it's confusing that you talk about reflective and non-reflective surfaces. Readers will just assume these things. Also, in this part you say a point light source, but I can't figure a point light source generating a cardioid. Finally, what is a catacaustic?

In the conchoid section, does the length have to be 2d? It might be interesting to explain what shape will result if a different length is used. Also, define the diameter of a cardioid.

In the inverse section, put a mouse over for focus. Also, say that k is the inversion radius.

Define cusp

Microphone section

Define pick up pattern, polar pattern, sound pressure level, etc.

Where is the front of a microphone?

Mandelbrot set

This totally came out of the blue.. it needs more explanation and a bunch of terms defined.

Caustics

Consider putting this section under the other caustics section

Active Comments

Re-order the description of each way of generating a cardioid

It sounds like the order we decided on when we talked was: 1) a description of the way of generating the cardioid (these will probably have to be a bit longer than they currently are), 2) introduction of the fancy term (evolute, etc. - you probably won't need to make anything a mouse-over given this structure), 3) equations (if and where we want them). (Abram, 7/9)

I reordered these. 7/13

Derive equations for the cardioid

Maybe derive the basic equations for the cardioid, if that interests you. The easiest way is probably to derive the parametric equations for x and y, and then use those equations to show that the polar and cartesian equations also work. (Abram, 7/9)

Refer the reader to images

There are lots of places where it seems like you want the reader to notice things about a picture, or where helps explain text, but you don't explicitly refer the reader to the image (I understand the anchoring of images may come later). (Abram, 7/9)

The microphone section is a little confusing and could be expanded

The microphone section overall could be a bit more clearly written (I trust you to find a way of doing this). One question I have in particular is what shape the microphone itself is, if the "cardioid" doesn't refer to the shape of the microphone itself. Overall, it may help to use a picture to describe in some detail what happens with the microphone. The section could end up being a good twice as long as a result, but it seems worth it. (Abram, 7/9)

It's not much longer, but I do think it's more clear and I've got a new picture. 7/13

The Mandelbrot section is a bit confusing

I can come up with specific ideas if you want. (Abram, 7/9)

Yeah, we'll have to talk about this. I spent this morning looking for more information but I can't really find anything. I don't really understand what's on the page right now anyway, I just took it from Wikipedia. Maybe we can go over this? 7/13

Remove those awful math terms from the basic description and why it's interesting

Both these sections have words like "evolute", "caustic", etc. They don't bother me, because I know enough math to know that hardly anybody bothers learning what these terms mean, but a non-mathematical reader may get intimidated because they think that they really ought to know these things. (Abram, 7/9)