Programming :: Algorithm For Finding The Shortest Path Between Geocoordinates?
Jun 27, 2011
AStar works on the basis of straight lines, AFAIK. In my case, we have geocoordinates and I can get the straight line distance between the waypoints. But I am wondering how approximate will the route calculated on this basis be? The actual distance "by road", which actually matters can be different.
Example. Assuming A and B are on the same plane, and will be equidistant from the goal point, if we consider a straight line between A and the goal point and, B and the goal point. The distance "by road" between A and the goal point may be greater or lesser than B. But because the AStar works on the basis of straight lines, it will return both the routes as the shortest. If yes, then which algo should be considered , if we want the results on the basis of actual distance in Km/m?
im trying to write a makefile which contains :two cpp files and two header files. now i've put cppfiles in a folder called source whose path is: /root/workspace/source and header files in a folder called header whose path is:
/root/workspace/makedemo/header
my makefile is in the path:/root/workspace/makedemo my makefile was like this:
Code:
HEADERS = $(shell /root/workspace/makedemo/header ls *.h) SOURCES = $(shell /root/workspace/source ls *.cpp) COMPILERFLAGS = -W -Wall DEBUGFLAGS = -g
[code].....
im sure that i've given the correct path but it is showing errors like this:
[root@localhost makedemo]# make /bin/sh: /root/workspace/source: is a directory /bin/sh: /root/workspace/source: is a directory g++ -W -Wall -I. -o output g++: no input files make: *** [output] Error 1
I have a copy of the MD5 algorithm and I'm taking a look at the source. It's pretty interesting but there are a few things that I'm curious about and I was wondering if anyone a bit more intuitive than I could help me out.The function declarations in the MD5 files are a bit unfamiliar to me. There is a macro used called PROTO_LIST, which I'm still not sure as to what this thing is doing exactly, but it's littered everywhere throughout the source.The signature here isn't too unfamiliar to me with the exception of the position of the PROTO_LIST macro. So here is a function with an unnamed argument of type MD5_CTX*.To me, this resembles an initializer list found in C++ with constructors but I certainly don't think that is the case here. So my questions about this are (1) how is this legal code in C and (2) what functionality has the PROTO_LIST macro provided for the function?
Java applet not loading image with relative path(e.g. images/1.jpg) but loads image with absolute path(i.e. from /root/user/images/1.jpg) . This is a problem when i want to host the applet on web server
I have a timer thread, and when it expires, it sets a flag. The only problem is, if any higher priority thread comes in between, then the timer is not expired in real time.Thus i want to set a highest priority to my thread. Now, i know 2 algos, which can make my thread in real time are: SCHED_FIFO and SCHED_RR.
So, here are my queries: 1) Which scheduling algo is best suited for this purpose? 2) Is it guaranted to work in real time if i use that algo (you suggest in 1) and set the max_priority by getting the maximum settable priority for that particular algorithm using, int sched_get_priority_max(int policy);
I've got a bit of an obscure question for you to test your brains a wee bit. I'm trying to implement a search program to find areas of high density in a binary string.
Where density is the number of 1's / number of digits with a maximum number of digits being the current number in a buffer (in this example 50). So for the example the density for the whole buffer is 15/50. But the density of Buffer[14..20]=[1110001]=4/7. So if looking for areas of density = 1/3 it would find the longest sequences of density over 1/3.So in the example. Buffer[4..9]=[100101]=3/6=1/2 which is above 1/3 but it is within the Buffer[4..48]=[100101000011100010000001000100100001001011001]=15/45=1/3
I have an algorithm guys called "Self Configurable Diagnosis Algorithm" but i don't have program for this.help me regarding that program and which type of Tcl script will be better suitable for that.
I need to simulate dijsktra's algorithm using network animator of ns2. how to write a tcl script for my code. This tcl script runs the dijsktra code and simulates its running on network animator.
i try to understand this algorithm but i cann't. [URL] I encounter problem understand the algorithm of fixed base windowing exponentiation algorithm ? What is fixed base in the first place ? How this algorithm works ?
algorithm:breada input: file system block number for immediate read file system block number for asynchronous read output:buffer containing data for immediate read { if(first block not in cache) { get buffer for first block if(buffer data not valid) initiate disk read } if(second block not in cache) { get buffer for second block) if(buffer data valid) //line 1 release buffer else initiate disk read //line 2 } if(first block was originally in cache) //line 3 { read first block return buffer } sleep (event first buffer contains valid data) return buffer }
Here is an algorithm for block read algorithm. I have problem in line 1: If buffer data is valid why is it releasing the buffer? line 2: If buffer data valid why is it initiating disk read. It should have read directly from buffer? line 3: It should be the first condition as if it is there in cache then it should return it without delay?
The algorithm for reading and writing disk blocks use the algorithm getblk to allocate buffers from the pool. In the algorithm getblk, if the kernel removes a buffer from the free list, it must raise the processor priority level to block out interrupts before checking the free list. Why ?Where can i find the C implementation of the above algorithm for buffer allocation in the linux source code ?
How do i find the correct path to my cd-rom drive? I want to install office 2007 using wine and I have used the programmerfish tutorial and now have to do the following:type wine /path to cd/setup.exe but I cannot seem to find the correct path.
-I tried /dev/sr0/setup.exe but it returned an error. -I tried /dev/sr0/media/setup.exe. returned the same error. -I tried /dev/media/setup.exe. Also no good.
I thought using df would help me and there i found /dev/sr0/ would be my cd-rom drive. Dunno it this correct though.
I am total new to linux as I worked mostly on RTOS (symbian). My problem is, I need to find the file IOSTREAM.H and I am following commands below: 1) cd / 2) find . iostream.h ( finds the file / directory from the current path) It shows No such File or Directory
I want to simulate a serial protocol in user space program to test reception algorithm. The protocol is similar to UART protocol but frame format is different. The duration of 1 bit is 114,46 us. In my main function I'm creating two threads. Tx for simulating transmitting data and Rx for reception data. For measure time I use create_timer() function and signals. Each thread has its own timer and signal handler. Tx timer uses SIGUSR1 and Rx timer uses SIGUSR2. Tx thread sets the global variable and Rx reads it.
The timers are set to sample with 114,46 us period. When they reach this value signal handler should set the flag. Flag is check in thread and some operation are made. When I set the timers period for longer time (100 ms) everything works fine but when I change it to default value (114,46 us) the Rx thread doesn't receive the proper data. I am wondering if the 114,46 timer period is possible to simulate in user space? Whether the time will give me the proper resolution ? Theoretically it should provide 1 ns resolution.
Does anyone know how to get the path with a inode number by C programming? Or can I get the absolute path without giving a "path" but a inode number by C?
like this: get_path(unsigned inode); not such this function: getcwd(".", xxx); taowuwen@gmail.com
using Ubuntu file browser, I browsed my Windows network and logged on to a Windows PC. Now Ubuntu file browser shows me "C$ on WinPC" as a folder. I can open it, read/write files, etc.But from bash prompt, I don't see anything of type CIFS/SMBFS listed in the output of "mount". Only the usual suspects (like local CDROM). How can refer to Windows files from Linux commandline?
I have thousands files in thousands subfolders. All subfolders are named differently, but all files named like:
I have to replace "AAA_000" with the path of the file.
For example if I have a file AAA_000_001.tif in Foled/sub1/sub2, I have to rename AAA_000_001.tif to Foled/sub1/sub2_001.tif (or Folder_sub1_sub2_001.tif)
So far I have this script:
It can replace all AAA of all files in all subfolders with BBB, but I did not find a way to replace it with the path.
I've been dabbling in IDL lately, and it seems useful enough, but occasionally I come across a problem like this: I'm trying to call an IDL procedure from within an IDL script which is called from a .csh script. (Don't ask, trust me, you don't want to know.) The IDL procedure may or may not be in the same directory as the .csh, so I'm calling it by it's full path: /home/ic/rad_sim However, all IDL will do is give me a syntax error and tell me ic is an undefined variable. Putting ic in double quotes makes the undefined variable error go away, but it still reports a syntax error.
I'm the server guy which is why I don't know this, but were staging a new webserver and we use some custom perl scripts and as were moving the site over for testing, apache is blowing a perl error;Can't locate web.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.0 /usr/local/share/perl/5.10.0 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /home/mcp/htdocs/cgi-bin/newgraph.gif line 11.,Now I can copy that file local, but there are a bunch of things, so the question is how do you globally add a folder to the perl search path
I have made the installation of Qt4 in my Fedora/MacBookPro. It also got a first compiling and running a simple program. The point is that for the compiler to run I need to point out every time where the bin is located, as that:
$ /home/threader/kinetic/bin/qmake -project
I have tried the following, but it still doesn't work:
# script #-----------------------------------------------------------# # /etc/bashrc or /home/threader/.bash_profile # config to Qt compiler
I'm using bash scripting to find any file that matches a path governed by the following regular expression:
"(monthly|nightly).[0-9]+/home/(user1|user2)/.mailbox/" to match files like: monthly.9/home/user1/.mailbox/l23131564 nightly.15/home/user2/.mailbox/cur/6546213
I want to share file locations with pc users (i'm a mac user). problem is: mac uses fslash, while pc files are indicated with baskslashes. I'm looking for a automation/plugin/shortcut/... to change them quick. I use paths a lot and share them with pc users, so manually it's to time consuming.
Is there a way to get the full path of a file in C? I have a method that accepts a file name as an argument and is supposed to read the content of the file. The file name might include "../" so this might lead to accessing files outside of the current directory. I tried to use fstat but I could not figure out how to get the full path.
I'm still going through "Agile Web Development with Rails" (Beta version), and I'm confused as to why some code in the book is not working for me. Following their example code in the book, I created code like so:
Code:
$ rails demo # ... $ cd demo/ $ script/generate controller Say index hello goodbye exists app/controllers/
[code]...
After starting the server, I can view the index view and the other views just fine. But then I have trouble if I add this code to any of the view html templates:
Code:
<p><%= link_to "Hello", say_hello_path %></p>
I'm told this is supposed to generate a link to the say/hello view. But instead I get an error message like so:
Code:
undefined local variable or method `say_hello_path' for #<ActionView::Base:0xb6ce3090> If I edit it to
