transformation

I have a Core Data model with a single transformable attribute. I also have this attribute use a custom NSValueTransformer, setup in the model properly. When I use mogenerator to generate/update my machine and human files, the machine files for the entity containing this attribute always type the attribute to NSObject. In order for Core Data to use my custom value transformer, this type needs to be the type the transformer understands. Right now, I manually do this in the human file by redefining the property with the proper type. This does the job and gets the transformer working. However, I

I would like to know best way to replace groupByKey operation with another. Basically I would like to obtain an RDD[(int,List[Measure]) , my situation: // consider measures like RDD of objects measures.keyBy(_.getId) .groupByKey My idea is to use reduceByKey instead, bacause it cause less shuffle: measures.keyBy(_.getId) .mapValues(List(_)) .reduceByKey(_++_) But I think is very inefficient cause it force me to instantiate a tons of unnecessary List objects. Can anyone have others idea to replace groupByKey? Another way is using aggregateByKey , which is specifically for combining values into

I have an image containing: a set of coordinates that act as orientation markers. a set of coordinates containing data. Let's call this image A. This image is fed to a scanner that returns a copy of the image with certain transformations applied (rotation, scale, translation). Let's call the transformed image B. The transformation values applied are not know to me, of course. Once I receive the transformed image (B), I can easily track the coordinates of the orientation markers and calculate the angle of rotation, scale (x,y) and translation (x,y). Now I need to retrieve the data coordinates

how do we extract scale matrix from model view matrix? Right now I am taking length of each coloumn, but it fails when the scale is negative. here is my code: float xs = matrix[0][0] * matrix[0][1] * matrix[0][2] * matrix[0][3] < 0 ? -1 : 1; float ys = matrix[1][0] * matrix[1][1] * matrix[1][2] * matrix[1][3] < 0 ? -1 : 1; float zs = matrix[2][0] * matrix[2][1] * matrix[2][2] * matrix[2][3] < 0 ? -1 : 1; glm::vec3 new_scale; new_scale.x = xs* glm::sqrt( matrix[0][0] * matrix[0][0] + matrix[0][1] * matrix[0][1] + matrix[0][2] * matrix[0][2]); new_scale.y = ys* glm::sqrt( matrix[1][0] * matrix[1

have a little problem here: int IntegerTransformer::transformFrom(std::string string){ stream->clear(); std::cout<<string<<std::endl;; (*stream)<<string; int i; (*stream)>>i; std::cout<<i<<std::endl; return i; } I by calling this function with the string "67" (other values dont work too) i get this output: 67 6767 Did you notice there are two std::cout in the function itself? Beside that also add this: stream->str(""); //This ensures that the stream is empty before you use it. (*stream)<<string; By the way, why don't you use boost::lexical_cast ? int IntegerTransformer::transformFrom(std: