math

问题 I want to add an electronic signature to a pdf. i am using signature pad library for capturing signature and sticker view for moving, scaling and rotating image StickerView. I am rendering the PDF in android using PDFView library to render PDF. i am using PDFbox by tomroush to manipulate pdf in android. i want to add image of signature to the pdf. but there is problem in mapping android view coordinates to pdf box coordinates. i am attaching code for what i have tried //loading pdf pdfView

问题 I want to add an electronic signature to a pdf. i am using signature pad library for capturing signature and sticker view for moving, scaling and rotating image StickerView. I am rendering the PDF in android using PDFView library to render PDF. i am using PDFbox by tomroush to manipulate pdf in android. i want to add image of signature to the pdf. but there is problem in mapping android view coordinates to pdf box coordinates. i am attaching code for what i have tried //loading pdf pdfView

问题 I need to convert coordinates X, Y into Latitude and Longitude. I've read wikipedia map projections, similar stackoverflow forums, applied my custom solutions and still didn't work. The coordinates I get from my formula are wrong, Longitude is acceptable but Latitude is not. I don't see where my calculous is wrong. The X,Y Point is taken from a JLayeredPane with the size of a background Map image, once a smaller image is released on this Map image, the point is taken. public void

问题 I can do this on paper easily enough but have a bit of a mental block in getting this into a language (I'd take any answer but Java probably easiest). I have two sets of points Point A (xA, yA) and Point B (xB, yB). Knowing this, and assuming that these two create a straight line graph I need to be able write a function that will give me xC given that I would know yC (and, obviously that the new point is on the same line). All help appreciated :) Kind Regards 回答1: (yB-yA)/(xB-xA) = (yC - yA)

问题 I essentially just want to make a ball bounce from say 100x to 300x... I looked for parabolic equations and then at trig functions and I can't seem to get it to work right... its been a while since I've done math so I probably am not even approaching this right... Here is my code for the whole bounce, if anyone can point me in the correct equation that would be wonderful. private void btStart_Click(object sender, EventArgs e) { lbBall.Location = new Point(0, 0); bounceBall(lbBall, 100); }

问题 I essentially just want to make a ball bounce from say 100x to 300x... I looked for parabolic equations and then at trig functions and I can't seem to get it to work right... its been a while since I've done math so I probably am not even approaching this right... Here is my code for the whole bounce, if anyone can point me in the correct equation that would be wonderful. private void btStart_Click(object sender, EventArgs e) { lbBall.Location = new Point(0, 0); bounceBall(lbBall, 100); }

问题 I have read the thread to make this happen for 4 points but only in 2D space here . I have implemented the answer for 3D but only for 3 control points here I have read this post but don't understand the sudo code or the math Can anyone simplify in java? I don't want to draw the curve as 2 segments of 3 points 回答1: Formula for cubic Bezier curve component (say X): X(t) = P0.X*(1-t)^3 + 3*P1.X*(1-t)^2*t + 3*P2.X*(1-t)*t^2 + P3.X*t^3 where P0 and P3 are end points, and P1 an P2 are control

问题 I have read the thread to make this happen for 4 points but only in 2D space here . I have implemented the answer for 3D but only for 3 control points here I have read this post but don't understand the sudo code or the math Can anyone simplify in java? I don't want to draw the curve as 2 segments of 3 points 回答1: Formula for cubic Bezier curve component (say X): X(t) = P0.X*(1-t)^3 + 3*P1.X*(1-t)^2*t + 3*P2.X*(1-t)*t^2 + P3.X*t^3 where P0 and P3 are end points, and P1 an P2 are control

问题 Actually this question or this puzzle needs the heroes in mathematics :) I have some image and i want to add some selection box to make a crop .. for that i want to control from point 2 to scale horizontally or vertically .. I find some nice code but it is make scaling eventually in x and y with each together so i am making some manipulation to be able scale any axis dependently .. I have get success to do that in Y axis but no success for X axis This is the code : case MotionEvent.ACTION

问题 I have the following lambda calculus: 1) λx . katze(x)(Garfield) 2) λP . λx . P(x)(tea) 3) λy . λx . likes(x, y)(Mia) How do I reduce them with the Beta Reduction? My solutions: 1) katze (Garfield) 2) tea 3) likes(Mia) 回答1: When performing beta reduction, you substitute the bound variable to the lambda function with the value supplied. The notation for that is [param := value] and you pick up the first variable that is given. In the case λx . katze(x)(Garfield) -> katze (Garfield) the