math - transfer the co-ordinates error in function -


i trying transfer coordinates of points new generated system coordinates

the original points in original system in top left corner ....

i wrote following function transfer coordinates
using formal got question pre_question question has 2 photos show mean , sign each part

the problem , getting negative value w ! can please check function , let me know problem

thanks

{

cvpoint transfer_coordinate (cvpoint pt1 , cvpoint pt2 , cvpoint pt3 , cvpoint pt4 , cvpoint origin , cvpoint current) { // pt1 , pt2 ==> points in line z  // pt3 , pt4 ==> points in line w  double a1 , a2 , b1 , b2 , d1 , d2;  d1= sqrt(pow((pt1.x - pt2.x),2.0)+ pow((pt1.y - pt2.y),2.0));  d2= sqrt(pow((pt3.x - pt4.x),2.0)+ pow((pt3.y - pt4.y),2.0));   a1 =(pt1.y-pt2.y)/d1; b1 =(pt2.x-pt1.x)/d1;  a2 =(pt3.y-pt4.y)/d2;  b2 =(pt4.x-pt3.x)/d2;   cvpoint new_point; //z = -sqrt(a1^2+b1^2)*(a2*(x-x0)+b2*(y-y0))/(a2*b1-a1*b2) //w =  sqrt(a2^2+b2^2)*(a1*(x-x0)+b1*(y-y0))/(a1*b2-a2*b1) //z new_point.x = -round(sqrt(pow(a1,2.0)+ pow(b1,2.0)) * (a2 * (current.x - origin.x) + b2 * (current.y - origin.y))/(a2 * b1 - a1 * b2)); // w new_point.y = round(sqrt(pow(a2,2.0)+ pow(b2,2.0)) * (a1 * (current.x - origin.x) + b1 * (current.y - origin.y))/(a1 * b2 - a2 * b1));   cvpoint reverse_point;  //x = x0 - b1*z/sqrt(a1^2+b1^2) + b2*w/sqrt(a2^2+b2^2) //y = y0 + a1*z/sqrt(a1^2+b1^2) - a2*w/sqrt(a2^2+b2^2) //x reverse_point.x = round (origin.x - b1 * new_point.x / sqrt(pow(a1,2.0) + pow(b1,2.0)) + b2 * new_point.y /sqrt(pow(a2,2)+ pow(b2,2))); //y reverse_point.y = round (origin.y + a1 * new_point.x / sqrt(pow(a1,2.0) + pow(b1,2.0)) - a2 * new_point.y /sqrt(pow(a2,2)+ pow(b2,2)));  //printf("\n points in z line (%d,%d),(%d,%d) , points in w line (%d,%d),(%d,%d) , origin (%d,%d)",pt1.x,pt1.y,pt2.x,pt2.y,pt3.x,pt3.y,pt4.x,pt4.y,origin.x,origin.y); //printf("\n current point = (%d,%d) , new point = (%d,%d) , reverse point = (%d,%d)" , current.x,current.y,new_point.x,new_point.y,reverse_point.x,reverse_point.y);  return new_point ;

}

}

if w-axis corresponds x-axis, affine transformation matrix m = [r]*[t], r rotation matrix phi angle , t translation matrix x0, y0

r = cos(phi) -sin(phi) 0     sin(phi)  cos(phi) 0     0         0       1

and

t = 1  0  0     0  1  0     dx dy 1

you have multiply these matrices m matrix , inverse matrix mr = inverse(m). can use m , mr transform coordinates xy wz system , vice versa [xnew, ynew, 1] = [xold, yold, 1] * [m]

more information here


Comments

Post a Comment

Popular posts from this blog

Why does Ruby on Rails generate add a blank line to the end of a file? -

running rails generate controller foo home results in: class foocontroller < application controller def home end end (there's nothing on line in actual file, blank line) is there purpose blank line? it's common use newline indicate end of line, last line. many editors (like vi, use) add in newline silently. consensus text files (especially in unix world) should end in newline, , there have been problems historically if wasn't present. why should text files end newline? the tool used count lines in file "wc" counts newlines in file, without trailing newline show 3 instead of 4. it improves readability of templates used in generator. consider: https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/controller/templates/controller.rb to remove trailing newline, template have last line of: end<% end -%> instead of: end <% end -%> that seems less readable me. the discussion below refers ...
Read more

keyboard - Smiles and long press feature in Android -

i've created android keyboard. how add features inserting smilies, , using long keypresses display symbols? to create long-press behavior allows select several options pop-up menu, follow guide (specifically pop-up menu section): http://developer.android.com/guide/topics/ui/menus.html smileys (also known emoticons) combination of keys, understood programs , parsed same way. have do, when clicks smiley face on keyboard, simulate pressing of key combination matching emoticon. example, when clicks smiley, should simulate key presses ':' , ')' :). here's list of emoticons: http://en.wikipedia.org/wiki/list_of_emoticons
Read more

node.js - Bad Request - node js ajax post -

i'm using express 3.0 , node v0.11.0. have button submits form , i'm using ajax post data json object node server. client code is: $('#contact').submit(function(e) { console.log('submit called'); var formdata = json.stringify($('form').serializeobject()); console.log(formdata); $.ajax({ url: "http://localhost:3000/savedata/", type: "post", datatype: 'json', data: {objectdata: formdata}, contenttype: "application/json", complete: function() { console.log('process complete'); }, success: function(data) { console.log('process sucess'); }, error: function() { console.log('process error'); }, }); return false; }); then on server: var express = require('express'); var app = express(); app.set('views', __dirname + '/views'); app.set('view engine', 'jade'); app.use(express.bodyparser());...
Read more