I have caught myself in a issue, I know its not that difficult but I couldnt figure out how to implement it. I have an m file that looks like
clear;
PVinv.m_SwF=20e3
for m=1:1:70;
PVinv.m_SwF=PVinv.m_SwF+1e3;
Lmin = PVinv.InductanceDimens();
Wa_Ac = PVinv.CoreSizeModel();
PVinv.CoreSelect(Wa_Ac);
[loss_ind_core,loss_ind_copper] = PVinv.InductorLossModel(PVinv.m_L_Selected);
Total_Inductor_Loss=loss_ind_core+loss_ind_copper
plot(PVinv.m_SwF,Total_Inductor_Loss,'--gs');
hold on
xlim([10e3 90e3])
set(gca,'XTickLabel',{'10';'20';'30';'40';'50';'60';'70';'80';'90'})
grid on
xlabel('Switching Frequency [kHz]');
ylabel('Power loss [W]');
end
And the function that is of interest is CoreSelect(Wa_Ac)
function obj = CoreSelect(obj, WaAc)
obj.m_Core_Available= obj.m_Core_List(i);
obj.m_L_Selected.m_Core = obj.m_Core_Available;
end
I want to change the value of i from obj.m_Core_List(1) to obj.m_Core_List(27) within that for loop of main m file. How can I get the value of the function coreselect when I call it in main m file
For eg for m=1 to 70 I want the function to take the value of i=1 then execute till plot command and then same with but i=2 and so on
Any suggestion would be really helpful
I'm not sure I understand your question perfectly, but I think you want to pass an index i to the CoreSelect function, and loop i from 1 to 27 outside of the function. Try this:
function obj = CoreSelect(obj, WaAc, i)
...
end
for i=1:27,
PVInv.CoreSelect(WaAc,i);
end
Related
As a homework assignment, I'm writing a code that uses the bisection method to calculate the root of a function with one variable within a range. I created a user function that does the calculations, but one of the inputs of the function is supposed to be "fun" which is supposed to be set equal to the function.
Here is my code, before I go on:
function [ Ts ] = BisectionRoot( fun,a,b,TolMax )
%This function finds the value of Ts by finding the root of a given function within a given range to a given
%tolerance, using the Bisection Method.
Fa = fun(a);
Fb = fun(b);
if Fa * Fb > 0
disp('Error: The function has no roots in between the given bounds')
else
xNS = (a + b)/2;
toli = abs((b-a)/2);
FxNS = fun(xns);
if FxNS == 0
Ts = xNS;
break
end
if toli , TolMax
Ts = xNS;
break
end
if fun(a) * FxNS < 0
b = xNS;
else
a = xNS;
end
end
Ts
end
The input arguments are defined by our teacher, so I can't mess with them. We're supposed to set those variables in the command window before running the function. That way, we can use the program later on for other things. (Even though I think fzero() can be used to do this)
My problem is that I'm not sure how to set fun to something, and then use that in a way that I can do fun(a) or fun(b). In our book they do something they call defining f(x) as an anonymous function. They do this for an example problem:
F = # (x) 8-4.5*(x-sin(x))
But when I try doing that, I get the error, Error: Unexpected MATLAB operator.
If you guys want to try running the program to test your solutions before posting (hopefully my program works!) you can use these variables from an example in the book:
fun = 8 - 4.5*(x - sin(x))
a = 2
b = 3
TolMax = .001
The answer the get in the book for using those is 2.430664.
I'm sure the answer to this is incredibly easy and straightforward, but for some reason, I can't find a way to do it! Thank you for your help.
To get you going, it looks like your example is missing some syntax. Instead of either of these (from your question):
fun = 8 - 4.5*(x - sin(x)) % Missing function handle declaration symbol "#"
F = # (x) 8-4.5*(x-sin9(x)) %Unless you have defined it, there is no function "sin9"
Use
fun = #(x) 8 - 4.5*(x - sin(x))
Then you would call your function like this:
fun = #(x) 8 - 4.5*(x - sin(x));
a = 2;
b = 3;
TolMax = .001;
root = BisectionRoot( fun,a,b,TolMax );
To debug (which you will need to do), use the debugger.
The command dbstop if error stops execution and opens the file at the point of the problem, letting you examine the variable values and function stack.
Clicking on the "-" marks in the editor creates a break point, forcing the function to pause execution at that point, again so that you can examine the contents. Note that you can step through the code line by line using the debug buttons at the top of the editor.
dbquit quits debug mode
dbclear all clears all break points
I have two functions:
function [] = func_one()
S.pb = uicontrol('style','push','unit','pix','posit',[20 20 260 30],
'string','Print Choices','callback',{#func_two,S});
and I have the second function:
function [a] = func_two(varargin)
a = 'alon';
end
I want func_one to return the variable a of func_two. How can I do that please?
I tried:
function [a] = func_one()
But I guess I have to do something with 'callback',{#func_two,S})
Thank you all!
If, as you say, you want func_one to return the value a in func_two then the easiest way to do this without using a callback is:
function [a] = func_one()
S.pb = uicontrol('style','push','unit','pix','posit',[20 20 260 30],
'string','Print Choices');
a = func_two()
The above will allow you to say run a=func_one and a will be the string 'alon'.
If you really really want func_two() to be a callback of your pushbutton, and you want a='alon' to be assigned in the workspace of func_one (the function that calls func_two) then put this in func_two
assignin('caller','a',a)
And if neither is what you want, then maybe you can indicate why you want func_one to return what func_two returns - like the exact interaction you are hoping to have with your GUI and how it differs from what you're actually experiencing.
If you are designing a GUI programmatically, I suggest you use nested functions to share data. Example:
function IncrementExample()
x = 0;
uicontrol('Style','pushbutton', 'String','(0)', ...
'Callback',#callback);
function callback(o,e)
%# you can access the variable x in here
x = x + 1;
%# update button text
set(o, 'String',sprintf('(%d)',x))
drawnow
end
end
I've been looking around and I have not been able to find anything that has worked for me. I'm starting to learn more Lua and to start off I'm making a simple calculator. I was able to get each individual operation onto separate programs, but when I try to combine them I just can't get it to work. My script as it is now is
require "io"
require "operations.lua"
do
print ("Please enter the first number in your problem.")
x = io.read()
print ("Please enter the second number in your problem.")
y = io.read()
print ("Please choose the operation you wish to perform.")
print ("Use 1 for addition, 2 for subtraction, 3 for multiplication, and 4 for division.")
op = io.read()
op = 1 then
function addition
op = 2 then
function subtraction
op = 3 then
function multiplication
op = 4 then
function division
print (answer)
io.read()
end
and my operations.lua script is
function addition
return answer = x+y
end
function subtraction
return answer = x-y
end
function multiplication
return answer = x*y
end
function division
return answer = x/y
end
I've tried using
if op = 1 then
answer = x+y
print(answer)
if op = 2 then
answer = x-y
print(answer)
and I did that completing each operation. But it doesn't work. I can't even get the error code that it's returning because it closes so fast. What should I do?
In your example, make these changes: You require operations.lua without the extension. Include parameters in your operations function definitions. Return the operation expression directly versus returning a statement like answer = x+y.
All together:
Code for operations.lua
function addition(x,y)
return x + y
end
--more functions go here...
function division(x,y)
return x / y
end
Code for your hosting Lua script:
require "operations"
result = addition(5,7)
print(result)
result = division(9,3)
print(result)
Once you get that working, try re-adding your io logic.
Keep in mind that as it's coded, your functions will be defined globally. To avoid polluting the global table, consider defining operations.lua as a module. Take a look at the lua-users.org Modules Tutorial.
The right if-then-else syntax:
if op==1 then
answer = a+b
elseif op==2 then
answer = a*b
end
print(answer)
After: please check the correct function-declaration syntax.
After: return answer=x+y is incorrect. If you want set answer's value, set without return. If you want return the sum, please use return x+y.
And I think you should check Programming in Lua.
First of all, learn to use the command line so you can see the errors (on Windows that would be cmd.exe).
Second, change the second line to require("operations"). The way you did it the interpreter expects a directory operations with an underlying script lua.lua.
I have a function in matlab with something like this:
function [ out ] = myFunc(arg1, arg2)
times = [];
for i = 1:arg1
tic
% do some long calculations
times = [times; toc];
end
% Return
out = times;
end
I want to abort the running function now but keep the values of times which are currently already taken. How to do it? When I press strg+c, I simply loose it because it's only a local function variable which is deleted when the function leaves the scope...
Thanks!
Simplest solution would be to turn it from a function to a script, where times would no longer be a local variable.
The more elegant solution would be to save the times variable to a .mat file within the loop. Depending on the time per iteration, you could do this on every loop, or once every ten loops, etc.
Couldn't you use persistent variables to solve your problem, e.g.
function [ out ] = myFunc(arg1, arg2)
persistent times
if nargin == 0
out = times;
return;
end;
times = [];
for i = 1:arg1
tic
% do some long calculations
times = [times; toc];
end
% Return
out = times;
end
I'm not sure whether persistent variables are cleared upon Ctrl-C, but I don't think it should be the case. What this should do: if you supply arguments, it will run as before. When you omit all arguments however, the last value of times should be returned.
onCleanup functions still fire in the presence of CTRL-C, however I don't think that's really going to help because it will be hard for you to connect the value you want to the onCleanup function handle (there are some tricky variable lifetime issues here). You may have more luck using a MATLAB handle object to track your value. For example
x = containers.Map(); x('Value') = [];
myFcn(x); % updates x('Value')
% CTRL-C
x('Value') % contains latest value
Another possible solution is to use the assignin function to send the data to your workspace on each iteration. e.g.
function [ out ] = myFunc(arg1, arg2)
times = [];
for i = 1:arg1
tic
% do some long calculations
times = [times; toc];
% copy the variable to the base workspace
assignin('base', 'thelasttimes', times)
end
% Return
out = times;
end
I'm new to Lua, so (naturally) I got stuck at the first thing I tried to program. I'm working with an example script provided with the Corona Developer package. Here's a simplified version of the function (irrelevant material removed) I'm trying to call:
function new( imageSet, slideBackground, top, bottom )
function g:jumpToImage(num)
print(num)
local i = 0
print("jumpToImage")
print("#images", #images)
for i = 1, #images do
if i < num then
images[i].x = -screenW*.5;
elseif i > num then
images[i].x = screenW*1.5 + pad
else
images[i].x = screenW*.5 - pad
end
end
imgNum = num
initImage(imgNum)
end
end
If I try to call that function like this:
local test = slideView.new( myImages )
test.jumpToImage(2)
I get this error:
attempt to compare number with nil
at line 225. It would seem that "num" is not getting passed into the function. Why is this?
Where are you declaring g? You're adding a method to g, which doesn't exist (as a local). Then you're never returning g either. But most likely those were just copying errors or something. The real error is probably the notation that you're using to call test:jumpToImage.
You declare g:jumpToImage(num). That colon there means that the first argument should be treated as self. So really, your function is g.jumpToImage(self, num)
Later, you call it as test.jumpToImage(2). That makes the actual arguments of self be 2 and num be nil. What you want to do is test:jumpToImage(2). The colon there makes the expression expand to test.jumpToImage(test, 2)
Take a look at this page for an explanation of Lua's : syntax.