I didn't find any method on java api to do this... there is one like : line.contains(point).. but it says that line2d doesn't have any area so it will return always false..
Any idea ?
Compare point by point and see if the cursor matches it.
You can do the search using the for each loop described here.
You should compute the distance from the point to the line, and if it is sufficiently small, then consider the point being on the line.
Google "distance point to line" or "distance point to segment".
Related
My goal is to determinate if a point (coordinate) in Input is inside the polygon (both the point and polygon/multipolygon are geographic objects from postGIS). Now my query always return false.
Basically this always returns false even if the point is inside the polygon:
select st_contains(st_geomfromtext('POINT(42.17591110412206 13.716918686169493)',4326),st_geomfromkml('<Polygon><outerBoundaryIs><LinearRing><coordinates>13.722101,42.177614,0 13.72....... </Polygon>')
);
i truncated the kml of course, anyway the format is (lat,lng,0), also on the point i used 4326 and i'm not sure if the value is correct. Also i tried both
Point(LAT,LNG) and Point(LNG,LAT)
Could anyone help me? I'm really out of ideas, surely there is something wrong on my query.
Actually, regarding to official documentation (https://postgis.net/docs/ST_Contains.html):
boolean ST_Contains(geometry geomA, geometry geomB);
Returns TRUE if geometry B is completely inside geometry A.
A point cannot contain polygon ;)
I've recently encountered these two variables in some Velocity code:
$!variable1
!$variable2
I was surprised by the similarity of these so I became suspicious about the correctness of the code and become interested in finding the difference between two.
Is it possible that velocity allows any order of these two symbols or do they have different purpose? Do you know the answer?
#Jr. Here is the guide I followed when doing VM R&D: http://velocity.apache.org/engine/1.7/user-guide.html
Velocity uses the !$ and $! annotations for different things. If you use !$ it will basically be the same as a normal "!" operator, but the $! is used as a basic check to see if the variable is blank and if so it prints it out as an empty string. If your variable is empty or null and you don't use the $! annotation it will print the actual variable name as a string.
I googled and stackoverflowed a lot before I finally found the answer at people.apache.org.
According to that:
It is very easy to confuse the quiet reference notation with the
boolean not-Operator. Using the not-Operator, you use !${foo}, while
the quiet reference notation is $!{foo}. And yes, you will end up
sometimes with !$!{foo}...
Easy after all, shame it didn't struck me immediately. Hope this helps someone.
I'm trying to set a specific property to a non exact value, for example say that I want to define the height of a pine tree to usually between 3-80 m (according to wikipedia). Then I would like to set something like [[Has height::3-80]] (of course this doesn't work) and defining the unit to meters with "custom units". Then I would like to be able to query for example "trees that can reach the height of 70 meters" and the pine tree would be included. I've been searching and trying different angles for hours now and I can't figure it out. Tried with #set_recurring_event but that seems to be only for dates/time. Also understood how to set multiple values for a property with #arraymap but this doesn't seem to help me here. Really would appreciate help with this (it's probably very easy and right in front of me) Thx! COG
There's no such things. But you able to create template, with parameters you want. The you just use code kinda {{range|min|max|units}}. For example your range of heights looks like {{range|3|80|m}}.
I am using iText and am very new to it. There have been several situations where I think I could have figured out the problem with my code if I knew what I was doing - I use examples without knowing the workings behind the code, and even as I look at the source I can't figure out what the programmer was thinking.
What does setTextMatrix of contentByteArray in iText do? And how do I figure out the parameter values I need?
For example:
cb.setTextMatrix(1, 0);
The input parameters are x,y coordinates in points, unless CTM scaling was defined.
0,0 would be the bottom left of the template you are referencing.
The position is the 'baseline' of the text, rather than the top or the bottom.
Transcribed from this source:
https://sourceforge.net/p/itext/mailman/message/12855218/
first parameter sets left margin, second parameter sets bottom margin.
I know that tan(angle) gets me the tangent. But how do I do the "reverse tangent" so that I can get the angle given the length of both sides of the right triangle?
I'm assuming there is a method for this in math.h?
As others have mentioned, atan() is what you're looking for. Generally, the operation is referred to as "inverse tangent" or "arc tangent", not "reverse tangent". The name "atan" comes from "arc tangent". There's also an atan2() function which takes both the X and the Y coordinates as separate paramters and will give you an angle relative to the 0 mark whereas atan() will leave figuring out the quadrant as an exercise for the developer. Beware, however, that the atan2() function on certain older MS environments (or maybe visual studio libraries?) doesn't work quite right...
There should be an atan() function.
For example: http://www.acm.uiuc.edu/webmonkeys/book/c_guide/2.7.html
use atan()