I have made a calculator for simple operations but I cant figure out how should I add the operator signs next to the numerals that I am entering.
I created 2 functions 1 on the number being entered
-(IBAction)buttonDigitPressed:(id)sender
and another for the operation
-(IBAction)buttonOperationPressed:(id)sender.
calculatorScreen.text = [NSString stringWithFormat:#"%.2f",result];
This is for the result to be shown on the label calculatorScreen.
The result i would like would be something like "1+2*3/4" on the calculatorScreen.
Sorry if I misunderstand your question, but what you want is to display on your calculator app the full equation that you've input thus far (e.g. 63+42-62).
Like any other calculator, you should have 2 label, one for your current input, and one to show all that you've entered.(I'm guessing you need the latter)
With the second label up, you can add in the append function into your digitpressed, enter/= function, operation function. If you want to tweak it such 16+23-32 will show up as
1) 16+23
2) 39-32
3) 39-32=7
then you'll have to add in your own specific code. otherwise the label will input as 16+23-32 = 7
You can just append the character to whatever is already on calculatorScreen. Or you can save the current input in an instance variable and display where appropriate.
This is just a guideline, since I don't know the behavior of your calculator in case of this input: 1 + 2 * 3 (simple calculator will return 9, scientific will return 7).
Related
I am trying to make a calculator app in swift as a practise for my IOS development course. for that app I am trying to append a number to an existing double or integer after the user pressed on a specific button, but I don't know how.
if the user pressed on lets say a 5, then I want that the code should append that 5 to the numbers he pressed before
for instance:
the user has typed the following number:
6797.890
and now he wants to add the 5 to the existing number so that the number would be:
6797.8905
I really don't know how to do this in the code, and I really appreciate it if someone could help me by showing how or giving some resource website's for this problem
thanks a lot!
Benji
I know you mentioned that you are supposed to use an Int or Double, but I would try and use NSDecimalNumber and String if you can. It will give you the precision you want and has a convenient way to turn the string into an NSDecimalNumber, NSDecimalNumber(string: "6797.8905"), as well as back to a string, number.stringValue. You can enteredAmount != NSDecimalNumber.notANumber just in case your user input is incompatible.
You must process the input as a string. If you process it as a double, the trailing zero will be lost and your code will not be able to distinguish between adding "5" to 6797.890 and adding "5" to 6797.89
Only convert from String to Double in one direction (from input to data) after displaying the initial value.
I have a file with two sheets:
sheet_A
A B
1 Mr. Joe USD
sheet_B
A B
1 =sheet_A.A1 ???
sheet_B.B1 shall show the value USD. I know i could get it easily with =sheet_A.B1 but I do not want that.
If I enter into sheet_B.B1 =ADDRESS(ROW();COLUMN()-1) I get the output $C$1 and with =INDIRECT(ADDRESS(ROW();COLUMN()-1)) Mr. Joe.
How can I "navigate" through a chain sheet_B.B1 - sheet_B.A1 - sheet_A.A1 - sheet_A.B1?
Edit 1
Maybe I need something like this
=OFFSET(FORMULA(ADDRESS(ROW();COLUMN()-1);0;1)#
sheet_B.B2 shall show the content of sheet_A.B2 in relation of the value in sheet_B.A1
Here are two possibilities. Either formula produces USD in sheet_B.B1.
=INDIRECT(ADDRESS(ROW();COLUMN();;;"sheet_A"))
=VLOOKUP(A1;$sheet_A.A1:B1;2)
Documentation: ADDRESS, VLOOKUP.
EDIT:
One more idea: The following produces the string "=sheet_A.A1", which could be parsed for the sheet name and cell address. Perhaps you would like to use it to refer to sheet_A.B1.
=FORMULA(INDIRECT(ADDRESS(ROW();COLUMN()-1)))
However, as I commented, there is probably an easier way for what you are trying to accomplish.
Documentation: FORMULA.
EDIT 2:
Here is the formula you requested. It uses REPLACE to remove = at the beginning of the string.
=OFFSET(INDIRECT(REPLACE(FORMULA(INDIRECT(ADDRESS(ROW();COLUMN()-1)));1;1;""));0;1)
I have a code where the overall aim is the extract two numbers from a string.
I get the string located in a cell array. To easy this example I have made the string in the test below in my code. I want to extract 1400 in one cell and the 2 in a second cell. The code I have made is working fine, but I think it can be optimized (speed and condensed) a lot. Does any of you have any suggestions?
Code:
test{1,1}='1:1400 og 2-fold'
FD1=test{1,1};
C = strsplit(FD1);
C2 = cell2mat(cellfun(#str2num,strrep(C,':',' '),'un',0));
C3 = cell2mat(C(1,3));
C3=strsplit(C3,'-');
Dilut1=C2(1,2);
Fold1=str2double(C3(1,1));
It really depends on your general structure. For this case, you can split the string at colon, space and dash by using:
A = strsplit(test{1,1},{':',' ','-'});
and then simply extract the two numbers as the second and fourth element
Dilut1=str2num(A{2});
Fold1 = str2num(A{4});
But as said it really comes down to your general structure. The more cases you have to account for the longer the code.
Thus it would maybe be better if you could write out something like
test{1,1}='1 dilute 1400 fold 2';
Then you could split at spaces, and search for the word you are interested in and the next string is then the number, ie
A = strsplit(test{1,1});
Dilute = str2num(A{circshift(strcmp(A,'dilute'),1)})
Fold = str2num(A{circshift(strcmp(A,'fold'),1)})
Round 2: Picking out leaders in an email
Alrighty, so my next problem is trying to figure out who the leader is in a project. In order to determine this, we are given an email and have to find who says "Do you want..." (capitalization may vary). I feel like my code should work for the most part, but I really have an issue figuring out how to correctly populate my cell array. I can get it to create the cell array, but it just puts the email in it over over again. So each cell is basically the name.
function[Leader_Name] = teamPowerHolder(email)
email = fopen(email, 'r'); %// Opens my file
lines = fgets(email); %// Reads the first line
conversations = {lines}; %// Creates my cell array
while ischar(lines) %// Populates my cell array, just not correct
Convo = fgets(email);
if Convo == -1 %// Prevents it from just logging -1 into my cell array like a jerk
break; %// Returns to function
end
conversations = [conversations {lines}]; %// Populates my list
end
Sentences = strfind(conversations,'Do you want'); %// Locates the leader position
Leader_Name = Sentences{1}; %// Indexes that position
fclose(email);
end
What I ideally need it to do is find the '/n' character (hence why I used fgets) but I'm not sure how to make it do that. I tried to have my while loop be like:
while lines == '/n'
but that's incorrect. I feel like I know how to do the '/n' bit, I just can't think of it. So I'd appreciate some hints or tips to do that. I could always try to strsplit or strtok the function, but I need to then populate my cell array so that might get messy.
Please and thanks for help :)
Test Case:
Anna: Hey guys, so I know that he just assigned this project, but I want to go ahead and get started on it.
Can you guys please respond and let me know a weekly meeting time that will work for you?
Wiley: Ummmmm no because ain't nobody got time for that.
John: Wiley? What kind of a name is that? .-.
Wiley: It's better than john. >.>
Anna: Hey boys, let's grow up and talk about a meeting time.
Do you want to have a weekly meeting, or not?
Wiley: I'll just skip all of them and not end up doing anything for the project anyway.
So I really don't care so much.
John: Yes, Anna, I'd like to have a weekly meeting.
Thank you for actually being a good teammate and doing this. :)
out2 = teamPowerHolder('teamPowerHolder_convo2.txt')
=> 'Anna'
The main reason why it isn't working is because you're supposed to update the lines variable in your loop, but you're creating a new variable called Convo that is updating instead. This is why every time you put lines in your cell array, it just puts in the first line repeatedly and never quits the loop.
However, what I would suggest you do is read in each line, then look for the : character, then extract the string up until the first time you encounter this character minus 1 because you don't want to include the actual : character itself. This will most likely correspond to the name of the person that is speaking. If we are missing this occurrence, then that person is still talking. As such, you would have to keep a variable that keeps track of who is still currently talking, until you find the "do you want" string. Whoever says this, we return the person who is currently talking, breaking out of the loop of course! To ensure that the line is case insensitive, you'll want to convert the string to lower.
There may be a case where no leader is found. In that case, you'll probably want to return the empty string. As such, initialize Leader_Name to the empty string. In this case, that would be []. That way, should we go through the e-mail and find no leader, MATLAB will return [].
The logic that you have is pretty much correct, but I wouldn't even bother storing stuff into a cell array. Just examine each line in your text file, and keep track of who is currently speaking until we encounter a sentence that has another : character. We can use strfind to facilitate this. However, one small caveat I'll mention is that if the person speaking includes a : in their conversation, then this method will break.
Judging from the conversation that I'm seeing your test case, this probably won't be the case so we're OK. As such, borrowing from your current code, simply do this:
function[Leader_Name] = teamPowerHolder(email)
Leader_Name = []; %// Initialize leader name to empty
name = [];
email = fopen(email, 'r'); %// Opens my file
lines = fgets(email); %// Reads the first line
while ischar(lines)
% // Get a line in your e-mail
lines = fgets(email);
% // Quit like a boss if you see a -1
if lines == -1
break;
end
% // Check if this line has a ':' character.
% // If we do, then another person is talking.
% // Extract the characters just before the first ':' character
% // as we don't want the ':' character in the name
% // If we don't encounter a ':' character, then the same person is
% // talking so don't change the current name
idxs = strfind(lines, ':');
if ~isempty(idxs)
name = lines(1:idxs(1)-1);
end
% // If we find "do you want" in this sentence, then the leader
% // is found, so quit.
if ~isempty(strfind(lower(lines), 'do you want'))
Leader_Name = name;
break;
end
end
By running the above code with your test case, this is what I get:
out2 = teamPowerHolder('teamPowerHolder_convo2.txt')
out2 =
Anna
I've been looking throught the documentation, but can't seem to find the bit I want.
I have a for loop and I would like to be able to view every value in the for loop.
for example here is a part of my code:
for d = 1 : nb
%for loop performs blade by blade averaging and produces a column vector
for cc = navg : length(atbmat);
atb2 = (sum(atbmat((cc-(navg-1):cc),d)))/navg;
atbvec2(:,cc) = atb2;
end
%assigns column vector 'atbvec2' to the correct column of the matrix 'atbmat2'
atbmat2(d,1:length(atbvec2)) = atbvec2;
end
I would like to view every value of atb2. I'm a python user(new to MATLAB) and would normally use a simple print statement to find this.
I'm sure there is a way to do it, but I can't quite find how.
Thankyou in advance.
you can use disp in Matlab to print to the screen but you might want to use sprintf first to format it nicely. However for debugging you're better off using a break point and then inspect the variable in the workspace browser graphically. To me, this is one of Matlab's best features.
Have a look at the "Examine Values" section of this article
The simplest way to view it everywhere is to change this line:
atb2 = (sum(atbmat((cc-(navg-1):cc),d)))/navg;
Into this, without semicolon:
atb2 = (sum(atbmat((cc-(navg-1):cc),d)))/navg
That being said, given the nature of your calculation, you could get the information you need as well by simply storing every value of abt2 and observing them afterwards. This may be done in atbmat2 already?
If you want to look at each value at the time it happens, consider setting a breakpoint or conditional breakpoint after the line where abt2 is assigned.