How to split a number in MATLAB?

Does anyone know how to write a program in MATLAB that can round any number to any required digit?

• The program has to be formed in MATLAB, and then written to an excel document. The final product will look like this: 1st column of excel = number you want rounded, 2nd column of ...show more

• Answer:

  I am actually stumped. If I understand you correctly, you have to go from a vector of doubles: numbers = [3.1415 ; 1.2342 ; 34.1232 ; ...] digits = [2 ; 3 ; 1 ; ...] to a vector of doubles with the elements of numbers rounded to the corresponding decimal place: answers = [3.14 ; 1.234 ; 34.1] only using length(), size(), >, <, >=, <=, ==, ~=, |, ||, &, &&, ~, if, for, while, and switch I honestly don't know how it could be done. If you were allowed to use round and the normal math functions, it'd be easy. If you could cast to an int and back to a double (and use math), it would be relatively simple. If you could convert the number to a string, you could parse it with nothing more than a loop and conditionals. Use of sprintf() would be even easier. The only way I can think of is if you can use xlsread() to pull in the data in string format, and manipulate it there without ever converting it to numbers (maybe only converting the digit you need to numbers, but that's not even necessary). But the prompt does talk about two vectors, one for each column, which is only really possible with numbers (strings would have to be stored in a cell array, or a character matrix). Heck, if you could just use + and - you could make a program with really really bad practices that would probably work for most cases within certain limits (that would also take a long time to run). If you could use ^ it might go a bit faster. But this prompt is ridiculous. Maybe ask for some clarification on which functions you really can't use? Converting to a string (sprintf() or num2str()) or manipulating the numbers after reading the data as a string would possibly be the easiest method that they might let you use. Also be sure to ask about converting to other numerical data types (like int).