zero

问题 I've got in the habit of using float f = 0.; //with a trailing period when assigning a zero value to a float in C. Should I be using float f = 0.f; //with an explicit float size or just stop messing about and use float f = 0; //with no trailing anything? Where did I pick up that habit and why? Is any version more right or wrong than any other? 回答1: 0.0 and 0. are doubles, not floats. While it is legal to assign doubles to floats in C without an explicit cast, 0.0f or 0.f would be the correct

问题 In excel, I have a text string, which contains numbers and text, that I strip the numbers out of with a formula. However, sometimes it is possible that the text string will be blank to begin with so if this happens I use "" to return a blank instead of a 0. When I link this excel sheet to an access database it will not let me format this column as currency because it is picking up the "" as text along with the stripped out numbers as numbers. Any solutions on how to fix this? Is there another

问题 What is significant difference between following zero double variable declaration: 0.0 VS 0d double d1 = 0.0; double d2 = 0d; I understand that both these are better than just 0 ,because are more obvious for code reader. However 0.0 VS 0d difference is not clear for me. 回答1: There is no difference. Have a look at the Java Language Specification, section 3.10.2 DecimalFloatingPointLiteral: Digits . Digits opt ExponentPart opt FloatTypeSuffix opt . Digits ExponentPart opt FloatTypeSuffix opt

问题 I am doing a calculation with an array which is drawn from mysql and the problem is "division by zero" warning I am running a loop over this statment $v = (($v - $valuei)/($valuei) * 100); Here $v is is changing (let's say from 100 to 150 e.g 100, 101, 102, 103,...,150) and $valuei is the intial value of $v (i.e 100) So, when the calculation will start first output should be zero and I want that zero then why it gives a warning "Division By Zero " and also makes all the "$v" values equal to

问题 I have the same kind of problem described in this topic: Using fzero: Undefined function or method 'isfinite' for input arguments of type 'sym' Their answers really helped me, but I am still stuck. I also have to find the zeros of a function of w, this function is defined in several steps: So the only unknown is w, and I defined other objects such as: lambda= @(w) ((16*rho(i)*A(i)*w^2*Lprime(i)^2)/(E(j)*I(i)))^0.25; beta=@(w) lambda*b(i)^0.5; gamma=@(w) lambda*Lprime(i)^0.5; Then, I define a

问题 I use matlab for symbolic calculations. After long calculations I've got a function of x, which is the combination of bessel functions and I want to find it's zeros. For that purpose I use fzero function in Matlab. But while it works perfectly for single bessel functions, it wont work for the mine one. >> fzero(@(x)besselj(0,x), 3.5) ans = 2.4048 >> fzero(@(x)DELTA_xi, 3.5) ??? Undefined function or method 'isfinite' for input arguments of type 'sym'. Error in ==> fzero at 333 elseif

问题 If I have a matrix such as this: A=[ 8 3 67 8 2 0 0 0 0 0; 8 76 9 233 1 89 34 0 0 0; 98 23 87 9 3 24 64 45 1 0] and I use the command sort(A,2) it will sort alongside the columns but at the same time push the zeros forward. I would like to keep the 0's to the end for computing purposes later on in the code. I I have been looking for a command that does this, as I feel there is one. I have also generally been trying to sort, flip, and transpose to get what I want but Im at an impasse. 回答1: You

问题 I have some problems with a Data series because it has some zero values so there are some distributions who don't fit it. I've tried with the function fitdist and fitdistr but no one works. There are my data: Precp 28 8 0 107 339 231 308 226 302 333 163 92 48 17 101 327 424 338 559 184 238 371 413 261 12 24 103 137 300 446 94 313 402 245 147 70 8 5 59 109,2 493,6 374,5 399,3 330,5 183,8 341,1 91 127,5 15 69 165,8 337,9 255 309,3 352,7 437,5 420,4 295,6 141,7 3,4 16,2 58,9 55,5 203,1 235 300

问题 This question already has answers here : Filling missing dates by group (3 answers) Closed 12 months ago . Consider a fragmented dataset like this: ID Date Value 1 1 2012-01-01 5065 4 1 2012-01-04 1508 5 1 2012-01-05 9489 6 1 2012-01-06 7613 7 2 2012-01-07 6896 8 2 2012-01-08 2643 11 3 2012-01-02 7294 12 3 2012-01-03 8726 13 3 2012-01-04 6262 14 3 2012-01-05 2999 15 3 2012-01-06 10000 16 3 2012-01-07 1405 18 3 2012-01-09 8372 Notice that observations are missing for (2,3,9,10,17). What I

问题 Is it perfectly ok (= well defined behaviour according to the standard) to call : mystream.read(buffer, 0); or mystream.write(buffer, 0); (and of course nothing will be read or written). I would like to know if I have to test if the provided size is null before calling one of these two functions. 回答1: Yes, the behavior is well-defined: both functions will go through the motions for unformatted input/output functions (constructing the sentry, setting failbit if eofbit is set, flushing the tied