# level curves in java

parasto harir

Greenhorn

Posts: 8

parasto harir

Greenhorn

Posts: 8

parasto harir

Greenhorn

Posts: 8

posted 3 years ago

Actually, I think you followed a link to a sponsor, not actually a reply to your question.

Can you explain how you'd draw these level curves without a program? If you can, we can probably help you translate the process into Java code.

Can you explain how you'd draw these level curves without a program? If you can, we can probably help you translate the process into Java code.

parasto harir

Greenhorn

Posts: 8

posted 3 years ago

Thank you for your reply,

Actually my program receives step size, first level and number of contours from user then it has to calculate the collection of all points (x,y) in the domain of a function f for which f(x,y) = c .

then it will show all level curves in related area

I want to have some result similar to this site:

http://mathdl.maa.org/images/upload_library/47/Seeburger/CalcPlot3D.htm

but I do not know how to find the exact value of x and y when f(x,y)= c ?

Actually my program receives step size, first level and number of contours from user then it has to calculate the collection of all points (x,y) in the domain of a function f for which f(x,y) = c .

then it will show all level curves in related area

I want to have some result similar to this site:

http://mathdl.maa.org/images/upload_library/47/Seeburger/CalcPlot3D.htm

but I do not know how to find the exact value of x and y when f(x,y)= c ?

parasto harir

Greenhorn

Posts: 8

Thank you for your reply,

Actually my program receives step size, first level and number of contours from user then it has to calculate the collection of all points (x,y) in the domain of a function f for which f(x,y) = c .

then it will show all level curves in related area

I want to have some result similar to this site:

http://mathdl.maa.org/images/upload_library/47/Seeburger/CalcPlot3D.htm

but I do not know how to find the exact value of x and y when f(x,y)= c ?

Actually my program receives step size, first level and number of contours from user then it has to calculate the collection of all points (x,y) in the domain of a function f for which f(x,y) = c .

then it will show all level curves in related area

I want to have some result similar to this site:

http://mathdl.maa.org/images/upload_library/47/Seeburger/CalcPlot3D.htm

but I do not know how to find the exact value of x and y when f(x,y)= c ?

posted 3 years ago

Well, that's a cool link. It doesn't seem to be calculating x and y for a given z though, like you would need to draw a topography map of a mountain. Instead it's drawing a three dimensional graph showing z values for all x, y over some range. It draws some lines on the graph for fixed values of x and y, but not fixed values of z.

Let's say that you actually do need to calculate

Let's say that you actually do need to calculate

**f(x,y) = c**though. You would need to solve for y in terms of x, and then plot that on a two-dimension graph. For example, you have the formula for a cone:**z=√ (x² +y²)**, and you want to solve that for z = 4. You rearrange it as**y = √(16 -x²)**, which gives you a circle with radius 4. Again, that's math though, not Java programing. You should have a firm grasp of the math before you even think about converting it to a program.
parasto harir

Greenhorn

Posts: 8

posted 3 years ago

Thanks for your reply =) and one more question

I have two frame and I defined two different canvas for each of them, one of them which I defined another class for that does not work with my code:

public class myCanvas extends GLCanvas {

private GL gl;

private GLAutoDrawable drawable;

public void paint(GLAutoDrawable drawable) {

GLUT glut = new GLUT();

GL gl = drawable.getGL();

gl.glBegin(GL.GL_LINES);

gl.glVertex3f(0.0f, -2.5f, 0.0f);

gl.glVertex3f(0.0f, 2.5f, 0.0f);

gl.glEnd();}

}

but this canvas works with this code:

public void paint(Graphics g) {

g.drawOval(13, 23, 65, 66);

}

I do not what is wrong , because I need to draw my object by using those code, I call this class by " contour_canvas.paint(drawable); " in the main class?

I have two frame and I defined two different canvas for each of them, one of them which I defined another class for that does not work with my code:

public class myCanvas extends GLCanvas {

private GL gl;

private GLAutoDrawable drawable;

public void paint(GLAutoDrawable drawable) {

GLUT glut = new GLUT();

GL gl = drawable.getGL();

gl.glBegin(GL.GL_LINES);

gl.glVertex3f(0.0f, -2.5f, 0.0f);

gl.glVertex3f(0.0f, 2.5f, 0.0f);

gl.glEnd();}

}

but this canvas works with this code:

public void paint(Graphics g) {

g.drawOval(13, 23, 65, 66);

}

I do not what is wrong , because I need to draw my object by using those code, I call this class by " contour_canvas.paint(drawable); " in the main class?

parasto harir

Greenhorn

Posts: 8

posted 3 years ago

Hi,

yes it seems to be easy to calculate for y in terms of x, in f(x,y)=c . but I have to find a solution which is good enough for general types of equation. in your example it was easy to calculate y and x but for example in :

x² +y²+3+log(x)-cos(x+y) = c how should I solve that?

thanks

yes it seems to be easy to calculate for y in terms of x, in f(x,y)=c . but I have to find a solution which is good enough for general types of equation. in your example it was easy to calculate y and x but for example in :

x² +y²+3+log(x)-cos(x+y) = c how should I solve that?

thanks