What does gca mean?

hello together, I'm a Beginner and I have a friends' skript and I'm trying to understand it.

1.)I don't really understand the "set"/"get" programmation als well as the "gca"/the "1" in the first line...

2.) Furthermore I didn't understand what the: {\it t} stands for (last line)...

for a Diagramm he wrote:

set(gca,'XGrid','on', 'YGrid', 'on', 'Fontsize', 16, 'linewidth', 1)
x_axis = get(gca, 'xtik');
xlabel('time{\it t} [s]')

I've already been searching for this question, but too many other questions without any correlation to this theme were found...

Thanks!

Answer 1

[Jan]

I agree with John: Only reading the manual will really help.

But this is a forum for Matlab related questions and all questions are welcome. Therefore:

gca replies the "handle" of the currently active axes object. A "handle" is a kind of address to identify all graphic objects. With set and get you can change or obtain properties of the graphic object.

Try this in the command window:

H = axes
get(H)
get(H, 'XColor')
set(H, 'XColor', [1,0,0]);
get(H, 'XColor')

'{\it t}' is a LaTeX string, which displays the "t" in italics. Search for "latex" in the documantation:

docsearch latex

Note that "get(gca, 'xtik')" will fail, because the property is called "xtick".

Answer 2

[John D'Errico]

Is there a reason why you would not just try

help gca

or better,

doc gca

RTFM. When you have a question about a MATLAB function, the fastest way to answer the question is by using the existing help. Well written, by professionals.

gca: Get handle to current axis.

I think your real problem is you have no idea how handle graphics works, based on your comments. Again, read the help. The help docs discuss the concept of "Graphics Objects".

[Charl Pieterse]

I agree with your comments John (go find help for yourself), however they are not helpful to the human asking the question. I'm in the same boat as the human asking the question, I've looked at help, doc and multiple internet searches. Matlab help is NOT helpful when you are just starting out. I've been working with it for 4years now at university and MOST/ nearly every answer to a question assumes a higher level of understanding. I have very RARELY found help for matlab useful. I have just started a course (8weeks ago) in python and it's like a breath of fresh air when you type a question and a human has answered it in your language. Personally I feel more confident in python after only 8weeks than i do after 4years of matlab. I appreciate the power of matlab, but it would be more inclusive if explanations weren't so illusive... or if people took a breath and thought about the human asking the question.

[Walter Roberson]

Kingshuk comments to @John D'Errico:

This message is discouraging the OP and others from asking questions and is rather talking about how stupid and illiterate the OP is. No one is perfect and forums exist for all questions , while help and doc do help , its not always understandable especially for a beginner , so other the rant , explanation could have been done.

[John D'Errico]

@Kingsuk

I'm sorry, but I disagree. It points out that the very best and fastest way to get an explanation for some function is to use the help already provided in MATLAB. You get an answer immediately, complete with mutliple examples, especially if you use the doc facility in MATLAB. This is certainly true for GCA.

In the case of the second question: 2.) Furthermore I didn't understand what the: {\it t} stands for (last line)... The answer is probably less obvious.