Shape Transformers and Interfaces OpenCV3.0 - transform

I was trying to make use of the new Shape Transformers and Interfaces of OpenCV3.0. Unfortunately it doesn't work as expected. To ensure not making any fancy warps and getting strange results cause of that reason I initialized a transformation where nothing at all should happen. But output of the transformation for a testpoint is always [0,0] and the warped image is always completley gray. Any suggestions what could be wrong are welcome.
int main(void){
Mat img1 = imread("C:\\opencv\\sources\\samples\\data\\graf1.png", IMREAD_GRAYSCALE);
std::vector<cv::Point2f> points1, testpoints;
vector<DMatch> good_matches;
Mat respic, resmat;
points1.push_back(Point(0, 0)); //Corners 800x600 pic
points1.push_back(Point(799, 0));
points1.push_back(Point(799, 599));
points1.push_back(Point(0, 599));
Mat pointmatrix1(points1);
good_matches.push_back(DMatch(0, 0, 0));
good_matches.push_back(DMatch(1, 1, 0));
good_matches.push_back(DMatch(2, 2, 0));
good_matches.push_back(DMatch(3, 3, 0));
testpoints.push_back(Point(250, 250));
Mat testpointsmat(testpoints);
// Apply TPS
Ptr<ThinPlateSplineShapeTransformer> mytps = createThinPlateSplineShapeTransformer(0);
mytps->estimateTransformation(pointmatrix1, pointmatrix1, good_matches); // Using same pointmatrix nothing should change in res
mytps->applyTransformation(testpointsmat, resmat);
cout << "pointmatrix1 = " << endl << " " << pointmatrix1 << endl << endl;
cout << "testpointsmat = " << endl << " " << testpointsmat << endl << endl;
cout << "resmat = " << endl << " " << resmat << endl << endl; //Always [0,0] ?
imshow("img1", img1); // Just to see if I have a good picture
mytps->warpImage(img1, respic);
imwrite("Tranformed.png", respic);
imshow("Tranformed", respic); //Always completley grey ?
waitKey(0);
return 0;
}

Don't ask me why but if I add this two lines it works.
// Apply TPS
transpose(pointmatrix1, pointmatrix1); // ADD
transpose(testpoints, testpoints); // ADD
Ptr<ThinPlateSplineShapeTransformer> mytps = createThinPlateSplineShapeTransformer(0);
Now There is something strange in source code here why cols and not rows.
by LBerger

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C++ difftime() alwas returns 0

In this Book object I created a system to keep track of the time a book has been checked out... there is a tm* called dateCheckedOut to store the date that the book is checked out.
int Book::getHeldTime()
{
time_t now ;
time(&now);
tm* t = localtime(&now);
double difference = difftime(now, mktime(dateCheckedOut))/(60 * 60 * 24);
cout << dateCheckedOut->tm_mon << dateCheckedOut->tm_mday << dateCheckedOut->tm_year << endl; //prints out 231117, which is correct.
cout << t->tm_mon << t->tm_mday << t->tm_year << endl; //prints out 34117, which is also correct
cout << difftime(now, mktime(dateCheckedOut)) << endl; //prints out 0
cout << difference << endl; //prints out 0;
return (int)(difference); //returns 0
}
I am quite confused because I checked the date when its checked out and the date when it is loaded, both are correct, but the difftime function just returns 0. Is there anything that might cause this code to not work? Thank in advance!
P.S. dateCheckedOut only has tm_mday, tm_mon, and tm_year set to the correct value, the rest are all not set. Is that a problem?

Program loop bug

Thanks for reading my problem. My loop code is not working as expected. The console output must not display negative numbers but it still does display them.
While (x > 0 && Y > 0)
{
--x;
--y;
cout << x << endl;
cout << y << endl;
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I'm still a beginner in c++.
'Y' and 'y' are different. Perhaps you want to write it this way:
while (x > 0 && y > 0)
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// First print the value and then decrement it
cout << x << endl;
cout << y << endl;
--x;
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Printing dynamically stored string in assembly mips32

I'm working on a mini-compiler and I reached the code generation level.
I want to store a string dynamically to the heap segment, so I wrote this C++ code (cg is the file I'm generating assembly code to) :
int length = strlen("abc");
cg << "\tori\t$a0,$0," << (length + 3) * 4 << endl; // reserve space for type + length + null + size
cg << "\tori\t$v0,$0,9" << endl;
cg << "\tsyscall" << endl;
increamentSP();
cg << "\tsw\t$v0,0($sp)" << endl;
cg << "\tori\t$t1,$0,1" << endl; // store the type
cg << "\tsw\t$t1,0($v0)" << endl;
cg << "\tori\t$t1,$0," << length << endl; // store the length
cg << "\tsw\t$t1," << 4 << "($v0)" << endl;
for (int i = 0; i < length; i++)
{
cg << "\tori\t$t1,$0," << (int)p->val[i] << endl; // store the char
cg << "\tsw\t$t1," << (2 + i) * 4 << "($v0)" << endl;
}
cg << "\tsw\t$0," << (2 + length) * 4 << "($v0)" << endl;
Basically, what I'm trying to do is :
First, I want to store a flag (1) referring that this type is a string to the first location.
Then, I want to store the size of my string to the second location.
After that, I want to store my strings chars to the next locations.
Finally, I want to store a null-terminating char to the last location.
My problem is that when I try to print my string using a code like this :
la $a0,8($t0)
ori $v0,$0,4
syscall
The result is that mips prints only the letter 'a', how can I print a string stored like this? or is there any better way to store my string?
p.s. I know I can use .asciiz in the .data segment, but the problem is that in my code I might edit the string, so I don't exactly know what my string would become.
Can any one help me with that?

Find angle of right angled triangle

I am trying to work out the angle of a right angled triangle. I have an array containing the lengths of the two sides of the triangle. I also have an array containing the Euclidean Distance between these two points. How would I find the angle of the triangles? In other words, how would I do the sin and then arcsin methods to find the angle? I am just looking for the angle opposite of the hypotenuse. I'm trying to do this in C++.
Solved it now, misinterpreted what I had been asked to do
Solution: How would I find the angle of the triangles
#include <iostream>
#include <cmath>
using namespace std;
#define radians(x) return x * (180/pi)
int main()
{
double opposite, adjacent, angle1, angle2, angle3, choice, radians, hypotenuse;
cout << "Opposite: ";
cin >> opposite;
cout << "Adjacent: ";
cin >> adjacent;
cout << "Radians or Degrees: (R/D)";
cin >> choice;
if(choice == "R")
{
angle1 = arctan(adjacent/opposite);
hypotenuse = opposite\cos(radians(angle1));
angle2 = arcsin(adjacent\hypotenuse);
cout << "Angle 1: "<< radians(angle1) << endl;
cout << "Angle 2: "<< "90\n";
cout << "Angle 3: "<< radians(angle2) << endl;
cout << "Hypotenuse: " << hypotenuse;
}
else if(choice = "D")
{
angle1 = arctan(adjacent/opposite);
hypotenuse = opposite\cos((angle1));
angle2 = arcsin(adjacent\hypotenuse);
cout << "Angle 1: " << (angle1) << endl;
cout << "Angle 2: " << "90\n";
cout << "Angle 3: " << (angle2) << endl;
cout << "Hypotenuse: " << hypotenuse;
}
return 0;
}
or just
angle2 = 180 - (angle1 + 90)
The relation between sides and angles of triangle is:-
a/sinA = b/sinB = c/sinC
where 'a' is the side opposite angle 'A'.
You know one angle let's say it's A = 90. Then you can calculate other two angles from above equation.
You have the lengths of the sides, if you us tangents, you can find the angle for the corresponding side.
Also, once you find one angle, all you need to do is subtract 90 from it to get the final angle:
tan(angle) = opposite/adjacent;
angle = arctan(opposite/adjacent);
otherAngle = 90 - angle;

VTK: display subdivided polygon

I have created an icosahedron and subdivided it, I am not trying to display it but it seems to be displaying it un-subdivided. Here is my code:
vtkSmartPointer<vtkPlatonicSolidSource> icosahedron = vtkSmartPointer<vtkPlatonicSolidSource>::New();
icosahedron->SetSolidTypeToIcosahedron();
icosahedron->Update();
cout << " Centre is " << icosahedron->GetOutput()->GetCenter()[0] << ", " << icosahedron->GetOutput()->GetCenter()[1] << ", " << icosahedron->GetOutput()->GetCenter()[2] << endl;
cout << " There are " << icosahedron->GetOutput()->GetNumberOfPolys() << " triangles." << endl;
cout << " there are " << icosahedron->GetOutput()->GetNumberOfPoints() << " points " << endl;
vtkSmartPointer<vtkPolyDataAlgorithm> subdivisionFilter;
subdivisionFilter = vtkSmartPointer<vtkLinearSubdivisionFilter>::New();
dynamic_cast<vtkLinearSubdivisionFilter *> (subdivisionFilter.GetPointer())->SetNumberOfSubdivisions(2);
subdivisionFilter->SetInput(icosahedron->GetOutput());
subdivisionFilter->Update();
cout << " After " << endl;
std::cout << " There are " << subdivisionFilter->GetOutput()->GetNumberOfPoints() << " points." << std::endl;
std::cout << " There are " << subdivisionFilter->GetOutput()->GetNumberOfPolys() << " triangles." << std::endl;
vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(subdivisionFilter->GetOutputPort());
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);
//Add the actors to the scene
renderer->AddActor(actor);
renderer->SetBackground(.1, .2, .3);
//Render and interact
renderWindow->Render();
renderWindowInteractor->Start();
The console output is:
Centre is 0, 0, 0
There are 20 triangles.
there are 12 points
After
There are 162 points.
There are 320 triangles.
Confirming that it has indeed been subdivided.
I can see the divisions after turning on wireframe mode:
#include <vtkProperty.h>
....
actor->GetProperty()->SetRepresentationToWireframe();
What you are seeing is that the algorithm is adding the new points in the same plane as the existing triangle, so when you render the result as a surface it does not look any different.

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