Polynomial function Math urgent

in General Discussion » Other • 1 year ago

Hi everyone!!

I have a polynomial equation such as this one y = -0.001x4 + 0.018x3 - 0.656x2 + 8.213x + 346 .

My first question is what would be the quickest and easiest way to draw this in processing?

Furthermore I have another polynomial equation that stars and ends at the same point as the one above, is it possible to connect them in processing since I would like to colour its inside.

Any help would be greatly appreciated!!! :)

Replies(12)

salino_to..

Re: Polynomial function Math urgent

1 year ago

any ideas??

allonestr..

Re: Polynomial function Math urgent

1 year ago

Unless I've missed the point, is this what you had in mind?

size(200, 400);
float x, y;
float x4, x3, x2, x1, k;
for (x = 0; x < width; x+=0.01)
{
x4 = -0.001 * pow(x, 4);
x3 = 0.018 * pow(x, 3);
x2 = -0.656 * x * x;
x1 = 8.213 * x;
k = 346;
y = x4 + x3 + x3 + x1 + k;
point(x, y);
}

salino_to..

Re: Polynomial function Math urgent

1 year ago

Hi thank you very much, this is what I had in mind and a great starting point for me!!

I was wondering how one could move this further to the middle? cause I have tried everything but I get it never to move.

And if I would have another one( which almost mirrorers the function) and they would intersect, would it be possible to say the function should stop drawing when they both intersect? So not any higher...

And I would also like to colour it but I have only learned colouring with void draw, which gives me an error here.

Thank you very much for your help!!

// edit

Also I would like to delete the left side of the function and the right side of the other function that I want to add later on.

allonestr..

Re: Polynomial function Math urgent

1 year ago

Try changing the range of the for loop. I just chose 0 to width as I had no idea what your curve would look like.

You could have it from 20 to width, say, and shove it to the left by subtracting something from the x co-ordinate in point(x, y).

so something like

size(200, 400);
background(255);
float x, y;
float x4, x3, x2, x1, k;
//the point colour is set by the stroke colour
stroke(255, 128, 0);
for (x = 20; x < width; x+=0.01)
{
x4 = -0.001 * pow(x, 4);
x3 = 0.018 * pow(x, 3);
x2 = -0.656 * x * x;
x1 = 8.213 * x;
k = 346;
y = x4 + x3 + x3 + x1 + k;
point(x - 20, y);
//one way of getting a reflection
point(width - (x - 20), y);

//I also tried using ellipses
//it looked nicer with the loop increment = 0.1 not 0.01
// noStroke();
// fill(0, 128, 255);
// ellipse(x - 20, y, 3, 3);
}

Again, if you play with the range of the for loop, you will see that it's easy to stop the curve and its reflection from overlapping.

salino_to..

Re: Polynomial function Math urgent

1 year ago

ah perfect its getting better and better!!

Thank you so much!

Now I have to think a little about some math stuff first to be able to continue but this is already really helpful!!

kind regards

salino_to..

Re: Polynomial function Math urgent

1 year ago

Alright I have been looking at my stuff now and I will need to make some changes but it seems to be ok. Thank you for your help already.

I have a completely different question now, is it possible if I for example have 3 certain points that form a triangle to colour the inside of it but that are only made out of line functions.

like this

line(359,5,362,10);

line(362,10,358,15);

line(358,15,359,5);

since the fill function does not work for it...

is there any way ?

thank you!!

kind regards

!!!!!

edit:

ok I am also facing a new problem ^^

I would like to draw a leaf from a tree and I have all the values from the edges in a row in a ascii file so lets say I have all the x values(all left and all right) in a row and all the y values in a row.

so for example

line (data1 first value, data2 first value, data 1 second value, data 2 second value);

line(data1 second value, data 2 second value, data 1 third value, data 2 third value);

and so on

do you know how I could program that?

I dont know how I can tell processing to use the certain number at the certain point.

I could do it manually but I have many ascii files and this would take too long. So I would like to have one version with the variables (data1 first value, data 2 first value......) and then just change the ascii files later on.

but the colour example is still important as well.

So if you could help me one more time I would be really grateful!!

I think this would be the last time as well ^ ^

thank you!!

kind regards

PhiLho

Re: Polynomial function Math urgent

1 year ago

Mmm, sometime I frown when somebody multiply threads on the same topic, here I think you could have made new threads since you have very different questions...
Anyway.

First one: look at beginShape() and related.

Second one: well, it is a bit confusing, real example could have helped. But look at loadStrings(), I think.

salino_to..

Re: Polynomial function Math urgent

1 year ago

hello

thank you for your reply first of all.

yes I know it is very different, I wasnt sure if I should start a new thread.

Ok the beginShape seems to be the right thing, at the moment it doesnt seem to work when I use line functions but with vertex function it does what it is supposed to do. Thank you for that!

I have looked at loadStrings but I am not sure how I can actually manage to say alright I would like to use the second data from that file and then the first one from the second file at a specific point.

To clarify things: I have x values such 365 356 344 370 and so on in an ascii file. and y values in a different file

Now I would like to write

line(*use the first value of the file with the x values, then the first one of the y file, then the second one of the x file, and then the second one from y file)

for the next one it would be line(*use the second value of the file with the x values, then the second one in the y file, then the third one of the x file, and then the third one from y file

and so on.. so later on I can just swith the x and y files and get new lines that are being drawn.

there is only a space between the values in the ascii files.

thank you very much!!!

I really appreciate all the help!!

PhiLho

Re: Polynomial function Math urgent

1 year ago

No problem with the thread, my remarks were only indicative, for the future.

You have to load both files. Just read them at once, unless they are multimegabyte in size, it shouldn't be a problem.
Then you can use split() to get each part, and int() to convert these strings to integers.

salino_to..

Re: Polynomial function Math urgent

1 year ago

Edit!!!!! I opened a new thread since it got quite messy.

here is the link

https://forum.processing.org/topic/loading-string-and

thank you!

Alright

here is what I have so far and I am facing still a few problems...

As you can see I wrote down some questions on the right.

I am not sure on the part of how to convert the strings into integers as well...

Edit: And sometimes it also said it looks like I am trying to mix static and non static actions.

thank you for the help!!

String numbers[] = loadStrings("xb.txt");
// I decided to put everthing into one file

//string numbers = ??? Do I have to see them here??
int[] nums = int(split(numbers, ' '));// how daoes that work. It says the method split(String, char) in the type PApplet is not applicable for the arguments.
// I tried to change the "numbers" into lines like in the example but it gives me the same error
void setup() {
size(720,560);
background(255);
}

void draw() {



fill(244,45,67);

beginShape();
vertex(nums[0],nums[73]);
vertex(nums[1], nums[74]);
vertex(nums[2],nums[75]);
//.......
endShape(CLOSE);
}

PhiLho

Re: Polynomial function Math urgent

1 year ago

Move code to setup():

String[] numbers;
int[] nums;
void setup() {
size(720,560);
background(255);
numbers = loadStrings("xb.txt");
for (int i = 0; i < numbers.length; i++) {
nums = int(split(numbers[i], ' '));
// Do something with the content of nums, not sure how the lines are organized
}
}

salino_to..

Re: Polynomial function Math urgent

1 year ago

Ah hello

thank you for your reply

I have been working on my code with some help and at the moment it looks like this.

I have heard this should be working but I get an error

it says java.lang.NullPointerException and when I see the error message it says the file in my case now "334.txt" is missing or inaccessible...

however it is in a data folder inside the sketch folder

and I have done that a couple of times with images before and that always worked so I am not sure why it is not working,

and I have tried it with other txt files in the same folder as well but it gives me the same error.

the txt file says under kind: plain text

the privilege are open for every one as well...

do you have any suggestions what I could do?

here is the code

String numbers[] = loadStrings("334.txt");
int[] nums = int(split(numbers[0], ' '));
void setup() {
size(720,460);
background(255);
}
void draw() {
fill(245,245,220);
ellipse(346,480,70,120);
fill(0,0,0);
ellipse(346,410,3,30);
fill(244,45,67);
beginShape();
for(int i = 0; i < nums.length - 144; i ++) vertex(nums[i], nums[i + 144]);
for(int i = 0; i < nums.length - 144; i ++) vertex(nums[i + 72], nums[i + 144]);
endShape();
}

thank you!!

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