division

问题 I want to calculate the slope of a line. public sealed class Point { public System.Numerics.BigInteger x = 0; public System.Numerics.BigInteger y = 0; public double CalculateSlope (Point point) { return ((point.Y - this.Y) / (point.X - this.X)); } } I know that BigInteger has a DivRem function that returns the division result plus the remainder but am not sure how to apply it to get a double. The numbers I'm dealing with are far far beyond the range of Int64.MaxValue so the remainder itself

问题 I have some places in my code where I want to assure that a division of 2 arbitrary floating point numbers (32 bit single precision) won't overflow. The target/compiler does not guarantee (explicitly enough) nice handling of -INF/INF and (does not fully guarantees IEEE 754 for the exceptional values - (possibly undefined) - and target might change). Also I cannot make save assumtions on the inputs for this few special places and I am bound to C90 standard libraries. I have read What Every

问题 Using bcdiv, i can't divide with small float using scientific notation : Working code : bcscale(30); $a = '1' ; $b = '0.00000001'; $result = bcdiv($a, $b); var_dump($result); Results in : string(20) "100000000.0000000000" Non-working code : bcscale(30); $a = '1' ; $b = '1e-8'; $result = bcdiv($a, $b); var_dump($result); Results in : Warning: bcdiv() [function.bcdiv]: Division by zero in C:\wamp\www\utilitaires\test_bcdiv.php on line XX NULL How can i do this division properly, with the less

问题 I have two sparse matrices E and D, which have non-zero entries at the same places. Now I want to have E/D as a sparse matrix, defined only where D is non-zero. For example take the following code: import numpy as np import scipy E_full = np.matrix([[1.4536000e-02, 0.0000000e+00, 0.0000000e+00, 1.7914321e+00, 2.6854320e-01, 4.1742600e-01, 0.0000000e+00], [9.8659000e-03, 0.0000000e+00, 0.0000000e+00, 1.9106752e+00, 5.7283640e-01, 1.4840370e-01, 0.0000000e+00], [1.3920000e-04, 0.0000000e+00, 0

问题 I'm trying to learn Swift and I made a simple average function: func average(numbers: Int...) -> Float { var sum = 0 for number in numbers { sum += number } return Float(sum)/Float(numbers.count) } average(1,2,3,4,5,6) This gives me the correct result: 3.5 However, I am wondering why I have to cast both sum and numbers.count to floats. I tried casting this way: return Float(sum/numbers.count) but it gives me just 3.0 回答1: First, you should use Double and not Float. Float gives you very

问题 I have a JSlider with a min of 0 and a max of 10,000. I have the major tick marks set at 1,000. If I were to paint the labels now they would show up as 0, 1000, 2000, 3000, 4000, etc. What I would like to be shown would be 0, 1, 2, 3, 4, 5, etc. What would be a good way to accomplish this task? 回答1: using JSlider.setLabelTable(Dictionary) EDIT Alternatively you can rely on predefined label UI and just change the label text: Enumeration e = jSlider.getLabelTable().keys(); while (e

问题 I'm doing an integration program with Riemann sums for my Calculus class. I've decided to use C when computing my integrals, and I noticed a huge error in my program that derives from this problem. #include <stdio.h> #include <stdlib.h> #include <math.h> int main(int argc, char** argv) { double x = 2.0/20.0; printf("%1.50f \n", x); return (EXIT_SUCCESS); } The program gives me : 0.10000000000000000555111512312578270211815834045410. My question: Why does this happen? And how can I fix this? Or

问题 I'm rather confused about how the multiply and divide operations work in x86 assembly. For example, the code below doesn't seem too difficult since deals with 8-bit. 8-Bit Multiplication: ; User Input: ; [num1], 20 ; [num2] , 15 mov ax, [num1] ; moves the 8 bits into AL mov bx, [num2] ; moves the 8 bits into BL mul bl ; product stored in AX print ax But what happens when you want to multiply two 16-bit numbers? How would one multiply two 16 bit numbers the same way as it has been done with

问题 I'm trying to divide one timedelta object with another to calculate a server uptime: >>> import datetime >>> installation_date=datetime.datetime(2010,8,01) >>> down_time=datetime.timedelta(seconds=1400) >>> server_life_period=datetime.datetime.now()-installation_date >>> down_time_percentage=down_time/server_life_period Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for /: 'datetime.timedelta' and 'datetime.timedelta' I know this

问题 I have been referring to this post Drawing Sphere in OpenGL without using gluSphere()? which has helped me quite a lot but i'm stumped now. I have an octahedron in my scene and I would now like to recursively subdivide the triangles to create a sphere. I found this block of code which is supposed to carry out the subdivision for me but I don't understand it fully void subdivide(GLfloat v1[3], GLfloat v2[3], GLfloat v3[3], int depth) { GLfloat v12[3], v23[3], v31[3]; int i; if (depth == 0) {