fprintf('text %6d %5.3f %2.5e', 3223, pi, 3*pi) text 3223 3.142 9.42478e+000 help if IF Conditionally execute statements. The general form of the IF statement is IF expression statements ELSEIF expression statements ELSE statements END The statements are executed if the real part of the expression has all non-zero elements. The ELSE and ELSEIF parts are optional. Zero or more ELSEIF parts can be used as well as nested IF's. The expression is usually of the form expr rop expr where rop is ==, <, >, <=, >=, or ~=. Example if I == J A(I,J) = 2; elseif abs(I-J) == 1 A(I,J) = -1; else A(I,J) = 0; end See also relop, else, elseif, end, for, while, switch. Reference page in Help browser doc if type factorial function n = factorial(n) %FACTORIAL Factorial function. % FACTORIAL(N) for scalar N, is the product of all the integers from 1 to N, % i.e. prod(1:N). When N is an N-D matrix, FACTORIAL(N) is the factorial for % each element of N. Since double precision numbers only have about % 15 digits, the answer is only accurate for N <= 21. For larger N, % the answer will have the correct order of magnitude, and is accurate for % the first 15 digits. % % See also PROD. % Copyright 1998-2004 The MathWorks, Inc. % $Revision: 1.7.4.6 $ $Date: 2004/06/25 18:52:29 $ N = n(:); if any(fix(N) ~= N) || any(N < 0) || ~isa(N,'double') || ~isreal(N) error('MATLAB:factorial:NNegativeInt', ... 'N must be a matrix of non-negative integers.') end n(N>170) = 171; m = max([1; n(:)]); N = [1 1 cumprod(2:m)]; n(:) = N(n+1); factorial(-1) ??? Error using ==> factorial N must be a matrix of non-negative integers. help ops Operators and special characters. Arithmetic operators. plus - Plus + uplus - Unary plus + minus - Minus - uminus - Unary minus - mtimes - Matrix multiply * times - Array multiply .* mpower - Matrix power ^ power - Array power .^ mldivide - Backslash or left matrix divide \ mrdivide - Slash or right matrix divide / ldivide - Left array divide .\ rdivide - Right array divide ./ kron - Kronecker tensor product kron Relational operators. eq - Equal == ne - Not equal ~= lt - Less than < gt - Greater than > le - Less than or equal <= ge - Greater than or equal >= Logical operators. Short-circuit logical AND && Short-circuit logical OR || and - Element-wise logical AND & or - Element-wise logical OR | not - Logical NOT ~ xor - Logical EXCLUSIVE OR any - True if any element of vector is nonzero all - True if all elements of vector are nonzero Special characters. colon - Colon : paren - Parentheses and subscripting ( ) paren - Brackets [ ] paren - Braces and subscripting { } punct - Function handle creation @ punct - Decimal point . punct - Structure field access . punct - Parent directory .. punct - Continuation ... punct - Separator , punct - Semicolon ; punct - Comment % punct - Invoke operating system command ! punct - Assignment = punct - Quote ' transpose - Transpose .' ctranspose - Complex conjugate transpose ' horzcat - Horizontal concatenation [,] vertcat - Vertical concatenation [;] subsasgn - Subscripted assignment ( ),{ },. subsref - Subscripted reference ( ),{ },. subsindex - Subscript index Bitwise operators. bitand - Bit-wise AND. bitcmp - Complement bits. bitor - Bit-wise OR. bitmax - Maximum floating point integer. bitxor - Bit-wise XOR. bitset - Set bit. bitget - Get bit. bitshift - Bit-wise shift. Set operators. union - Set union. unique - Set unique. intersect - Set intersection. setdiff - Set difference. setxor - Set exclusive-or. ismember - True for set member. See also arith, relop, slash, function_handle. help for FOR Repeat statements a specific number of times. The general form of a FOR statement is: FOR variable = expr, statement, ..., statement END The columns of the expression are stored one at a time in the variable and then the following statements, up to the END, are executed. The expression is often of the form X:Y, in which case its columns are simply scalars. Some examples (assume N has already been assigned a value). for R = 1:N for C = 1:N A(R,C) = 1/(R+C-1); end end Step S with increments of -0.1 for S = 1.0: -0.1: 0.0, do_some_task(S), end Set E to the unit N-vectors for E = eye(N), do_some_task(E), end Long loops are more memory efficient when the colon expression appears in the FOR statement since the index vector is never created. The BREAK statement can be used to terminate the loop prematurely. See also if, while, switch, break, continue, end, colon. Reference page in Help browser doc for for k=1:10 z(k)= k^2; end z z = 1 4 9 16 25 36 49 64 81 100 for k=1:10 z(k)= k^2 end z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 z = 1 4 9 16 25 36 49 64 81 100 clear z for k=1:10 z(k)= k^2 end z = 1 z = 1 4 z = 1 4 9 z = 1 4 9 16 z = 1 4 9 16 25 z = 1 4 9 16 25 36 z = 1 4 9 16 25 36 49 z = 1 4 9 16 25 36 49 64 z = 1 4 9 16 25 36 49 64 81 z = 1 4 9 16 25 36 49 64 81 100 zz= [1:10].^2 zz = 1 4 9 16 25 36 49 64 81 100 help while WHILE Repeat statements an indefinite number of times. The general form of a WHILE statement is: WHILE expression statements END The statements are executed while the real part of the expression has all non-zero elements. The expression is usually the result of expr rop expr where rop is ==, <, >, <=, >=, or ~=. The BREAK statement can be used to terminate the loop prematurely. For example (assuming A already defined): E = 0*A; F = E + eye(size(E)); N = 1; while norm(E+F-E,1) > 0, E = E + F; F = A*F/N; N = N + 1; end See also for, if, switch, break, continue, end. Reference page in Help browser doc while x= 10; while x>3 disp(x), x=x-3; end 10 7 4 % infinite loops, while(1); 1= true; either "break", or ctrl c cd matlab\velocity\ open velocity2.m velocity(0.35, 0, 12, 0, 68.1, .25) Warning: Size vector should be a row vector with integer elements. > In velocity at 18 The velocity is 50.8012 m/s ans = 50.8012 velocity2(0.35, 0, 12, 0, 68.1, .25) ans = 50.8348 diary off