function-calls

I want to understand difference between ISR (Interrupt Service Routine) and Function call. I feel both the function call and ISR are the same from the hardware perspective. Please Correct me if I am wrong. All I could found about ISR and Function call is as follows: ISR: Asynchronous event that can occur any time during the execution of the program Saves the PC, Flags and registers on the stack and disables all the interrupts and loads the address of the ISR ISR cannot have arguments that can be passed to it Cannot return values Enables the interrupts Generally small as they are taking the

I tried to construct the clustering method as function the following ways: mydata <- mtcars # Here I construct hclust as a function hclustfunc <- function(x) hclust(as.matrix(x),method="complete") # Define distance metric distfunc <- function(x) as.dist((1-cor(t(x)))/2) # Obtain distance d <- distfunc(mydata) # Call that hclust function fit<-hclustfunc(d) # Later I'd do # plot(fit) But why it gives the following error: Error in if (is.na(n) || n > 65536L) stop("size cannot be NA nor exceed 65536") : missing value where TRUE/FALSE needed What's the right way to do it? Do read the help for

my question is probably very basic but I did not find an answer... I wrote a function (public checkSomething that gets 2 strings) in program.cs when I tried to call this function from static main I got this error: "An object reference is required for a non-static field, method or property 'checkSomething(string,string)' ". However,when I changed my main to Public (and not static)- there is no error. Why this happen? What is better - to have a Static main or not? Why would it even matter? thanks! The question here is not about static functions, but specifically why is main static in a C#

I have this code snippet that I use everywhere in my programs (C++ and OpenCV). It is for timing some operations: double t; // Some code... t = (double)getTickCount(); Object1.LotOfComputing(); t = 1000*((double)getTickCount() - t)/getTickFrequency(); cout << "Time for LotOfComputing =" << t << " milliseconds."<< endl; cout << "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=" << endl; This is how the OpenCV doc recommend to time a function/portion of code and it seems to works for me after using it for some weeks. The times I measure are ranging from about 1ms to 700ms, and I round them to the millisecond.

This question already has an answer here: Order of function calling 5 answers Is there some definite order in which the functions are called in the expression below or does it vary from compiler to compiler? Does the following rule apply here - In C, the order in which arguments to functions and operands to most operators are evaluated is unspecified. Found the above rule in this wiki page a = (f1(10, 20) * f2(30, 40)) + f3() The rule does apply. f1 , f2 , and f3 may be evaluated in any order. To expand a bit on some of the confusion (because people keep posting wrong answers ), operator