Rrerku

The following code renders the graphs of an arc of a circle and the standard parabola on the Cartesian plane. It is ridiculously small, though. How do I magnify the display, except for the labels on the axes? (I do not want to use pgfplots.)

documentclassamsart
usepackageamsmath
usepackageamsfonts

usepackagetikz
usetikzlibrarycalc,intersections



begindocument


noindent hspace*fill
begintikzpicture
%An arc of a circle centered at (0, 1/2) and the standard parabola are drawn on the Cartesian plane.
draw[fill] (0,1/2) circle (1.5pt);
draw[blue] ($(0,1/2) +(150:1/2)$) arc (150:390:1/2);
draw[domain=-sqrt(3)/2:sqrt(3)/2] plot (x, x*x);
draw[latex-latex] ($(-12.5pt,0) +(-1/sqrt(2),0)$) -- ($(12.5pt,0) +(1/sqrt(2),0)$);
draw[latex-latex] (0,-1/2) -- ($(0,3/4) +(0,12.5pt)$);
node[below right] at ($(1/sqrt(2), 0) +(12.5pt,0)$)textitx;
node[above right] at ($(0,3/4) +(0,12.5pt)$)textity;

endtikzpicture
hspacefill



enddocument

• I add scale option. I think scale=5 is appropriate in this case.


• I don't use your approach to center figures. I would use figure and add a caption as well as a label instead. If you don't want a caption and a label, you should use center environment.


• I changed a draw[fill] to fill.

documentclassamsart
usepackageamsmath
usepackageamsfonts
usepackagetikz
usetikzlibrarycalc,intersections
begindocument
beginfigure
centering
begintikzpicture[scale=5]
%An arc of a circle centered at (0, 1/2) and the standard parabola are drawn on the Cartesian plane.
fill (0,1/2) circle (0.3pt); % Note that it is not 1.5pt
draw[blue] ($(0,1/2) +(150:1/2)$) arc (150:390:1/2);
draw[domain=-sqrt(3)/2:sqrt(3)/2] plot (x, x*x);
draw[latex-latex] ($(-12.5pt,0) +(-1/sqrt(2),0)$) -- ($(12.5pt,0) +(1/sqrt(2),0)$);
draw[latex-latex] (0,-1/2) -- ($(0,3/4) +(0,12.5pt)$);
node[below right] at ($(1/sqrt(2), 0) +(12.5pt,0)$)textitx;
node[above right] at ($(0,3/4) +(0,12.5pt)$)textity;
endtikzpicture
captionSome caption
labelfig:tikzfigure
endfigure
enddocument

Or if you want to have your image automatically resized to textwidth, have a look at the nice tikzscale package.

beginfilecontentsmypic.tikz
begintikzpicture
%An arc of a circle centered at (0, 1/2) and the standard parabola are drawn on the Cartesian plane.
fill (0,1/2) circle (0.3pt);
draw[blue] ($(0,1/2) +(150:1/2)$) arc (150:390:1/2);
draw[domain=-sqrt(3)/2:sqrt(3)/2] plot (x, x*x);
draw[latex-latex] ($(-12.5pt,0) +(-1/sqrt(2),0)$) -- ($(12.5pt,0) +(1/sqrt(2),0)$);
draw[latex-latex] (0,-1/2) -- ($(0,3/4) +(0,12.5pt)$);
node[below right] at ($(1/sqrt(2), 0) +(12.5pt,0)$)textitx;
node[above right] at ($(0,3/4) +(0,12.5pt)$)textity;
endtikzpicture
endfilecontents

documentclassamsart
usepackageamsmath
usepackageamsfonts
usepackagetikz
usetikzlibrarycalc,intersections
usepackagetikzscale
usepackage[showframe]geometry
begindocument
beginfigure
centering
includegraphics[width=textwidth]mypic.tikz
captionSome caption
labelfig:tikzfigure
endfigure
enddocument

[First code improved]

I suggest not using a filled circle for coordinate. A node is more ok I think. Also a node is not scaled by scale.

documentclassamsart
usepackageamsmath
usepackageamsfonts
usepackagetikz
usetikzlibrarycalc,intersections
tikzsetyour coordinate/.style=fill=black,inner sep=0.5pt,circle
begindocument
beginfigure
centering
begintikzpicture[scale=5]
%An arc of a circle centered at (0, 1/2) and the standard parabola are drawn on the Cartesian plane.
node[your coordinate] at (0,1/2) ;
draw[blue] ($(0,1/2) +(150:1/2)$) arc (150:390:1/2);
draw[domain=-sqrt(3)/2:sqrt(3)/2] plot (x, x*x);
draw[latex-latex] ($(-12.5pt,0) +(-1/sqrt(2),0)$) -- ($(12.5pt,0) +(1/sqrt(2),0)$);
draw[latex-latex] (0,-1/2) -- ($(0,3/4) +(0,12.5pt)$);
node[below right] at ($(1/sqrt(2), 0) +(12.5pt,0)$)textitx;
node[above right] at ($(0,3/4) +(0,12.5pt)$)textity;
endtikzpicture
captionSome caption
labelfig:tikzfigure
endfigure
enddocument

You can (should) also apply this to the second code. Btw, I think your circle is way too small.

Another option that might help if you want to save scale for relative scaling and/or are using transform shape is just to redefine the unit vectors. In this example, this is equivalent to Joule V's suggestion, but in the above-mentioned situations it might be useful to know about this option, too.

documentclassamsart
usepackageamsmath
usepackageamsfonts
usepackagetikz
usetikzlibrarycalc
begindocument
begintikzpicture[x=5cm,y=5cm]
draw[fill] (0,1/2) circle (1.5pt);
draw[blue] ($(0,1/2) +(150:1/2)$) arc (150:390:1/2);
draw[domain=-sqrt(3)/2:sqrt(3)/2] plot (x, x*x);
draw[latex-latex] ($(-12.5pt,0) +(-1/sqrt(2),0)$) -- ($(12.5pt,0) +(1/sqrt(2),0)$);
draw[latex-latex] (0,-1/2) -- ($(0,3/4) +(0,12.5pt)$);
node[below right] at ($(1/sqrt(2), 0) +(12.5pt,0)$)$x$;
node[above right] at ($(0,3/4) +(0,12.5pt)$)$y$;
endtikzpicture
enddocument