Hi all
I was just trying to make a new header definition that could report
appropriately, dependant on presence of a coordinate system, plan, extended
or projected elevation. It was mostly progressing OK until I realised I was
pinning my hopes on using the metapost ATTR__elevation variable in a block
of tex code. That and my very poor grasp of tex Boolean testing ( \if
ATTR__elevation is probably the wrong syntax) mean that I am probably
doomed to fail. Since I have got this far, I may as well ask a few
questions..
In the code below.
Is there a tex variable equivalent to the ATTR__elevation metapost
variable?
Is it possible to differentiate extended elevations from projected
elevations (and plans) with tex?
For example, can we determine the projection angle of a projected elevation?
How to format the magdecl output to just 1 decimal place?
Bruce
# % print coordinate system and projection related information
\if ATTR__elevation % print elevation specific text %THIS TEST ALWAYS
FALSE??
# % extended elevation
{\the\legendtextsize\ss {Idealised elevation} \par} %'
looking generally East' %this whole line probably redundant
# % projected elevation
\edef\tmp{\the\outcsname} \ifx\tmp\empty %ie if no cs
{\the\legendtextsize\ss {Elevation looking xxx deg
magnetic}\par} %NEED TO SEE IF PROJECTION ANGLE AVAILABLE TO TEX
\else %there is a cs
{\the\legendtextsize\ss\the\outcsname { elevation looking xxx
deg}\par} %NEED TO SEE IF PROJECTION ANGLE AVAILABLE TO TEX
\fi
\else % not ATTR__elevation % print plan specific text
# % plan
\edef\tmp{\the\outcsname} \ifx\tmp\empty %ie if no cs
%{\the\legendtextsize\ss {Plan projection (not
georeferenced)}\par} %remove preceding % for redundant long form
{\the\legendtextsize\ss Arrow points to
magnetic north}
\else %there is a cs
\the\legendtextsize\ss\the\outcsname %{ plan
projection}\par %remove preceding % for redundant long form
\edef\tmp{\the\northdir} \ifx\tmp\empty
\else
{\the\legendtextsize\ss {
arrow points \the\northdir { north}}} % grid or true north
\fi
# % Could report declination here
\edef\tmp{\the\magdecl} \ifx\tmp\empty \else
{\the\legendtextsize\ss\the\magdecl { deg magnetic
declination}\par} %HOW TO LIMIT TO ONE DECIMAL PLACE?
\fi
\fi
\par\par
\fi % ATTR__elevation % end plan
Above code produces the top couple of lines of this header snapshot. It
should be different depending whether it is a plan or elevation, but at
present is always this way. However the coordinate system test does work
properly.
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