Problemas con point(x,y); - Problems with point(x,y);

Programming Questions

Turriano

Problemas con point(x,y); - Problems with point(x,y);

in Programming Questions • 1 year ago

Hola amigos.
Tengo una fórmula matemática, que debería hacer unas curvas en la pantalla a base de

puntos:

int n=2;
int x=100;

while (x<=200) {

float decimal = (float)(Math.pow(x,1f/n));
int entero=floor(decimal);

double y = (floor((decimal-entero)*100));

x++;

// print (x); print (" "); println (y);

point(x,y);

}

Cuando lo imprimo en pantalla, me funciona:

print (x); print (" "); println (y);

Pero cuando lo intento usar para poner puntos en pantalla, no:

point(x,y);

¿En qué me equivoco?.

==================================================================================

Hello friends.
I have a mathematical formula, which should make some curves on the screen based on points:

int n=2;
int x=100;

while (x<=200) {

float decimal = (float)(Math.pow(x,1f/n));
int entero=floor(decimal);

double y = (floor((decimal-entero)*100));

x++;

// print (x); print (" "); println (y);

point(x,y);

}

When I print it on screen, I work:

print (x); print (" "); println (y);

But when I try to use to put points on the screen, no:

point(x,y);

What did I do wrong?.
Tanks.

Replies(18)

blooop15

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Your printing code looks fine although I would do it like this; You may have issues because you are mixing doubles and ints.

println(x+" "+y);

point(x,y);

kasperkam..

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Quizas podes poner un ellipse

               
                ellipse(x, y, 5, 5);

darkgisba

Re: Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

int n=2;
int x=0;
void setup(){
frameRate(5);
}
void draw(){
//while (x<=200) {
float decimal = (float)(Math.pow(x,1f/n));
int entero=floor(decimal);
float y = (floor((decimal-entero)*100));
x++;
// print (x); print (" "); println (y);
rect(x,y,0,0);
//}
}

That works, the problem was that the point function is not for shapes or points but for lights, and you were using doubles, where you should have used float instead.

Copy this code and see if thats what you want. I removed the while soo you can see your "shape" being drawn.

akiersky

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

I get an error from the point() method, which says it is expecting two floats.

If you change your point method to:

point( (float) x , (float) y );

that will cast the variables as floats, and they will display.

the other issue, is that your x value is starting at 100, which is the width of the default processing display. Processing sets the origin of drawing to the top left corner, so at 100, you are already off the right edge. if you add:

size(200, 200);

at the beginning, your points will show in the top right corner. alternately you could start your x at 0, then they would begin in the top left.

you may want to run through some of the tutorials here to get some more information about these and other things you may run into in your programming explorations: http://processing.org/learning/

good luck!

Arnaldex

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

No veo problema y hasta funciona. Quizas la versión de Processing? yo tengo 1.3.6

DB_87

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

If you want to plot an equation with a proper axes etc. then you might find the gwoptics library useful

http://gwoptics.org/processing/gwoptics_p5lib/

The example http://gwoptics.org/processing/gwoptics_p5lib/examples/Graph2D/Basic1/Basic1.pde should give you a good starting point for plotting a simple curve!

david_and..

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

seems to work fine with P2D renderer:

int n = 2;
int x = 100;
void setup() {
size(800, 800, P2D);
int i = 0;
}
void draw() {
while (x<=200) {
float decimal = (float)(Math.pow(x,1f/n));
int entero = floor(decimal);
float y = (floor((decimal-entero)*100));
x++;
println(x+", "+y);
point(x, y);
}
}

edit: with "float" instead of "double", that was the problem, but the thing goes off screen. you have to consider the area of work is a determined amount of pixels in your screen with 0,0 in upper left corner.

billhsu

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

A couple things: point(x, y) works with two ints or floats. y is a double.

Also, you're generating and displaying points outside your current default window.

If you make your window size bigger, you'll see the points.

Bill

kritzikra..

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

lol, this code made me giggle a bit.

i hope you understand that you're not printing the curve itself,

but only the amplified error that would occur if your calculation was performed using integers.

anyways, here's your cleaned up code, i changed as little as possible:

size( 400, 400 );
int n=2;
int x=100;
while (x<=200) {
float decimal = pow(x,1.0/n);
int entero=floor(decimal);
float y = (decimal-entero)*100;
x++;
print (x); print (" "); println (y);
point(x,y);
}

therealpo..

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

As a more elaborate correction and illustration of what's going on:

void setup() {
  size( 400, 400 ); 
  noLoop();
}

float n = 2.0;
int start_x = 100;

void draw() {
  background(255);

  // simple axis system
  fill(0);
  line(0,50,width,50);
  text("50",35,35);
  line(50,0,50,height);
  text("50",25,50);
  
  // draw scale/offset
  float y_scale = 5, y_offset = 100;

  // function drawing:
  float x=0,y=0,diff=0;
  for (x=start_x; x<=200; x++) {
    // getting y = f(x) = x^(1/n)
    y = pow(x, 1.0/n);
    stroke(0);
    point(x, y_scale*y+y_offset);

    // getting y = f(x) - floor(f(x))
    diff = y-floor(y);
    stroke(255,0,0);
    point(x, y_scale*diff+y_offset);
  } 
  
  // label the functions
  fill(0);
  text("f(x)",x+15,y_scale*y+y_offset);
  fill(255,0,0);
  text("f(x) - floor(f(x))",x+15,y_scale*diff+y_offset);
}

ingnia

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Try to use the command map(....) to avoid getting the points out of your workspace. Imagine that your workspace is 800x600 and your points are in the range of 900, 1000, etc; they won't be displayed. With map, you scale the points to a a constraint window.

I hope it helps.

scratchis..

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Hmmm. Did you try set(x,y,color(0))? Also, try setting the strokeWeight a bit higher. I had a friend that said he was having code troubles, and i solved it by handing out a magnifying glass so he could see the pixels. ::)

Turriano

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Hola amigos.
Primero, muchas gracias por ayudarme y gracias a vosotros, casi he terminado lo que me proponía.
Casi...

Con este programa, he logrado hacer líneas curvas y ya demuestro que los números aleatorios infinitos, están relacionados con Pi.

size(1000,500);
background(255,255,255);
int n=7;
   int y=0;

for (int cuenta=0; cuenta<15000; cuenta++)
{

float decimal = (pow(cuenta,1f/n));
    int entero=floor(decimal);

    float par = (decimal-entero)*100;
    float x = (floor(par));
    y++;


point(x,y);

print ("X: "); print (x);print (" Y: "); println (y);

}

Sin embargo, no consigo hacer una onda senoidal completa, cuando lo intento con este otro programa:

float TrozoX;

void setup(){
size(1000,500);
background(255,255,255);
TrozoX=0;
}

void draw(){

int n=3;

for(int TrozoY=0 ; TrozoY<50 ; TrozoY++){

for(int x=0 ; x<50 ; x++){

for(int y=0 ; y<50 ; y++){

double z=((Math.pow(x,n))+(Math.pow(y,n)));

float decimal = (float)(Math.pow(z,1f/n));
double entero=(Math.floor(decimal) );

double TrozoX=(Math.floor((decimal-entero)*100));

}

}

}

point(TrozoX,250);
}

¿Os importaía decirme que hago mal en este otro programa?.

¡Muchas gracias!

------------------------------------------------------------------------

Hello friends.
First, thank you very much for helping me and thanks to you, I'm almost done what I wanted.
Almost ...

With this program, I managed to make curved lines and demonstrate that infinite random numbers are related to Pi.

size(1000,500);
background(255,255,255);
int n=7;
   int y=0;

for (int cuenta=0; cuenta<15000; cuenta++)
{

float decimal = (pow(cuenta,1f/n));
    int entero=floor(decimal);

    float par = (decimal-entero)*100;
    float x = (floor(par));
    y++;


point(x,y);

print ("X: "); print (x);print (" Y: "); println (y);

}

However, I can not make a full sine wave, when I try with this other program:

float TrozoX;

void setup(){
size(1000,500);
background(255,255,255);
TrozoX=0;
}

void draw(){

int n=3;

for(int TrozoY=0 ; TrozoY<50 ; TrozoY++){

for(int x=0 ; x<50 ; x++){

for(int y=0 ; y<50 ; y++){

double z=((Math.pow(x,n))+(Math.pow(y,n)));

float decimal = (float)(Math.pow(z,1f/n));
double entero=(Math.floor(decimal) );

double TrozoX=(Math.floor((decimal-entero)*100));

}

}

}

point(TrozoX,250);
}

¿Os importaía decirme que hago mal en este otro programa?.

¡Muchas gracias!

maleo

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

what is the method (with three nested loops?) you're trying to get a "full sine wave" with?

do you want to achieve something like this:

void setup() {
size(1000, 500);
background(255);
}
void draw() {
point(frameCount%width, height/2 - height/2 * sin(frameCount/(width/PI/4)));
if (frameCount % width == 0) background(255);
}

Turriano

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Malchus thank you very much for your reply.
It's a very interesting routine and keep me to study it.
But my intention is to try to prove, that decimal places are obtained in one of the formulas of Fermat's Last Theorem, are related to Pi and are able to draw a sine wave.
This experiment is not the first time I do. Some time ago using a Sinclair Spectrum computer, is by the late 80's, I also realized that using the Basic Sinclair brought and that was very similar to Basic Qs that were on the first IBM PC.
I was trying to solve the theorem for pure hobby and gave me to collect some of the decimals, and translate them into the screen.
These two loops, make the calculation of the theorem and then root out "n" to check if the result is "0".
Well
If you run the program you have set up, with print numeric values, you will see that these values tend to drop-up of 0, then do just the opposite and reach maximum values -98, 97, 99 ... -.
If the instruction point (x, y)-coordinates-work well, I'm quite sure, that draw the expected sine wave.
It is a mathematical experiment-plot, I would like to continue work in the future.
The problem is I do not know to program in Java and I do not use any form of Basic. I like Procesing for many reasons, but I make a mess with many things, such as the type of variables.
I am sure that when you pick up confidence with this type of language and thanks to those who help me, of course, I'll get to have fewer problems when programming.
Best regards.

---------------------------------------------------------------------------

Muchas gracias Maleo por tu respuesta.
Es una rutina muy interesante y me la guardo para estudiarla.
Pero mi intención es intentar demostrar, que los decimales que se obtienen en una de las fórmulas del Ultimo Teorema de Fermat, están relacionados con Pi y son capaces de dibujar una onda senoidal.
Este experimento no es la primera vez que lo hago. Hace tiempo usando un ordenador Sinclair Spectrum, hallá por los últimos años 80, lo realicé también usando el Basic Sinclair que traía y que era muy parecido al Qs Basic que traían los primeros PC Ibm.
Estaba intentando resolver por puro pasatiempo dicho teorema y me dió por recoger parte de los decimales y plasmarlos en la pantalla.
Esos dos bucles, hacen el cálculo del teorema y luego se saca la raiz "n", para comprobar si el resultado es "0".
Pues bien:
Si corres el programa que he puesto arriba, con imprmir los valores numéricos, verás que estos valores tienden a bajar-subir de 0, para después hacer justo lo contrario y llegar a valores máximos -98, 97, 99...-.
Si la instrucción point(x,y) -Coordenadas- funcionara bien, estoy completamente seguro, que dibujaría la esperada onda senoidal.
Es un experimento matemático-gráfico, que me gustaría seguir indagando en el futuro.
El problema, es que no sé programar en Java y no quiero usar ningún tipo de Basic. Me gusta Procesing por muchos motivos, pero me hago un lío con muchas cosas, como el tipo de variables.
Estoy seguro, que cuando coja confianza con este tipo de lenguaje y gracias a los que me ayudáis, por supuesto, conseguiré tener menos problemas a la hora de programar.
Saludos cordiales.

maleo

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

turriano, that sounds very interesting. can you provide any websites or reference of the formulas you are referring to? maybe then I could better understand your algorithm and help you translate it into java/processing!

Turriano

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

Thanks again for answering me, maleo.
Although I am very clumsy in mathematics, I can not but admire the beauty of the latter.Several years ago, I was experimenting with "The Last Theorem of Fermat" in a 48K Spectrum.

This gentleman said: "To all: (a ^ n) + (b ^ n), there is always at least one outcome-c ^ n-accurate and always if a, b and c are natural numbers other than 0 and n greater than two ):

http://es.wikipedia.org/wiki/%C3%9Altimo_teorema_de_Fermat

So I did a double loop, to increase b, elevating Any summing. After n was the root of c checking whether it was 0.
Sometimes he got it and some do not. Now here I have the notes, but mostly I remember pairs of roots and little else.
Most of the time was a long list of infinite decimals. He left the computer for hours and watched him on television, then plugged in my old Spectrum at a TV station and when the ads came between films, I took a look.
One day I happened to catch two of the digits of each number and put in another counter, where x and y was fixed, that number was chopped and placed in a point (x, y) (By the way, much like this instruction Processing the curiously).
The formula for "chopping" the number was very similar to what I have in the current program with which you attempt to do so.
I'll explain step by step, what I mean:

Preparation screen:

TrozoX float;

void setup () {
  size (1000.500);
  background (255,255,255);
  TrozoX = 0;
}

Apart from the loop counters is to solve the formula:

double z = ((Math.pow (x, n)) + (Math.pow (y, n)));

This calculates the root "n" of the result:

float decimal = (float) (Math.pow (z, 1f / n));

This is cut or the first two decimal places, for placement in the chart:

double integer = (Math.floor (decimal));
double TrozoX = (Math.floor ((decimal-integer) * 100));

And this already, is the drawing of points, as they are calculating the coordinates:

point (TrozoX, 250);

And that's where I fail, since the rest works for me perfectly.

----------------------------------------------------------------------------------------------------------------

Gracias de nuevo por contestarme, maleo.

A pesar de que soy muy torpe en matemáticas, no puedo por menos de admirarme con la belleza de éstas.

Hace ya algunos años, estaba haciendo experimentos con "El Ultimo Teorema De Fermat" en un Spectrum 48K.

Este señor decía que: "Para todo: (a^n)+(b^n), hay siempre al menos un resultado -c^n- exacto y siempre si a, b y c, sean números naturales distintos de 0 y n mayor que dos):

http://es.wikipedia.org/wiki/%C3%9Altimo_teorema_de_Fermat

Así que hice un doble bucle, para incrementar a y b, elevándolos a n y sumándolos. Después hallaba la raíz n de c y comprobaba si era 0.

Unas veces lo obtenía y otras no. Ahora aquí no tengo los apuntes, pero sobre todo me acuerdo de raíces pares y poco más.

La mayoría de las veces era una larga lista de decimales infinitos. Dejaba el ordenador por horas y lo miraba por la televisión, pues conecté mi viejo Spectrum a una emisora de TV y cuando venían los anuncios entre película y película, lo echaba un vistazo.

Un día se me ocurrió coger dos de los decimales de cada número y colocarlos en otro contador, en donde la x era fijo e y, era dicho número troceado y lo coloqué en un point(x,y) (Por cierto, muy parecida esta instrucción a la de Processing, curiosamente).

La fórmula para "trocear" dicho número era muy parecida a la que tengo en el programa actual con el que intento hacerlo.

Te explico paso a paso, lo que pretendo:

Preparación pantalla:

float TrozoX;

void setup(){

size(1000,500);

background(255,255,255);

TrozoX=0;

}

Aparte de los bucles contadores, está la fórmula a resolver:

double z=((Math.pow(x,n))+(Math.pow(y,n)));

Esto calcula la raiz "n" del resultado:

float decimal = (float)(Math.pow(z,1f/n));

Esto corta o se queda con los dos primeros decimales, para colocarlos en el gráfico:

double entero=(Math.floor(decimal));

double TrozoX=(Math.floor((decimal-entero)*100));

Y esto ya, es el dibujo de lo puntos, según se van calculando las coordenadas:

point(TrozoX,250);

Y ahí es donde me falla, ya que el resto me funciona perfectamente.

maleo

Re: Problemas con point(x,y); - Problems with point(x,y);

1 year ago

hey turriano,

I put something together following your explanations:

//parameters
int n=3;
int xmax = 100;
int ymax = 100;
// running variables
int x = 0;
int y = 0;
float lastx = 0;
float lasty = 0;
void setup() {
size(1000, 200);
background(255);
stroke(0);
}
void draw() {
translate(0, height);
scale(1, -1);
float z = pow(pow(x, n) + pow(y, n), 1.0/n);
float dec = z - floor(z);
float pointy = map(dec, 0, 1, 0, height-1); // map to sketch height
float pointx = frameCount % width;
stroke(255);
line(pointx, 0, pointx, height-1);
stroke(0);
//point(pointx, pointy);
if (pointx > 0) {
line(lastx, lasty, pointx, pointy);
}
lastx = pointx;
lasty = pointy;
if (++y == ymax) {
x++;
y = 0;
if (x == xmax) {
println("done");
noLoop();
}
}
}

I made some changes using draw() instead of your x and y-loops. I also removed the TrozoY-loop which i think is usesless and just does the same thing 50 times.

You can change the parameters n, xmax and ymax to get different results.

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