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VecXYpline Class Function Manual |
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VecXYpline Class Function Manual |
Purpose
To get a value of an element at a particular index in a Vector. The return result is a VecPt2D object.
The first element index is 0, and the last one is n-1, where n is no of total elements.
Class
VecXYpline
Usage
{VecPt2D} ret = object({int} argm1)
argm1 = index number
Example:
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->v = VecXYpline() ->v.load("line_xy.txt") ->print v |
See also (class function)
init
Purpose
To increase the maximum size of the vector by a given number.
Class
VecXYpline
Usage
{void} object.EXTEND({int} argm1)
argm1 = number of elements wanted to extend
Example:
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->v = VecXYpline(5) ->v.maxsize() ->v.maxsize() |
See also (class function)
maxsize, truncate
Purpose
To find in a particular poly-line, a VecPt2D object, in a vector. Two poly-line objects are the same if their ID number are the same, thus content of poly-lines plays no roll.
The return result is an index of the vector, if found, otherwise it returns -1.
Class
VecXYpline
Usage
{int} ret = object.FIND({VecPt2D} argm1)
argm1 = poly-line wanted to find
Example:
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->print v ->pline1.id() = 1
->v.find(pline1) |
See also (class function)
Purpose
To initialize a vector object.
Please be aware that once the vector is initialized, it is still empty. Only its maximum number of element in the vector is declared. Use function "pushback" to insert element into a vector.
Class
VecXYpline
Usage
{void} object.INIT({int} argm1)
argm1 = number of maximum elements in the vector
Example:
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->v = VecXYpline() ->v.init(500) -> |
See also (class function)
pushback
Purpose
To get the last poly-line from the vector.
Class
VecXYpline
Usage
{VecIndx} ret = object.LAST()
Example:
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->print v |
See also (class function)
Purpose
To read data from an ASCII file and stored in a VecRCpline object.
If file name extension is omitted, the function will add default extensions to the files. The default extension of an ASCII data file is ".txt".
Unless the path name is given in the file names, the function will search for the files in the current working directory, defined by command "set path".
It is important to make sure that the poly-line ID appears right before the data. Each data line has exactly 2 fields, the first is for x coordinate and the second is for y coordinate. All of them are separated by at least one blank, a white space, ASCII 32.
It is possible to have a comment line in the data file, by inserting a slash sign, "/", in front of a line. Comment lines will not be read by the function.
The following is an example of 3 poly-lines stored in a file.
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Class
VecXYpline
Usage
{void} object.LOAD({String} argm1)
argm1 = data filename (default extension is ".txt")
Example:
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->v = VecXYpline() ->v.load("my_data") -> |
See also (class function)
save
Purpose
To report the maximum x, y coordinate in the vector by searching through all poly-lines in the vector.
Class
VecXYpline
Usage
{Pt2D} ret = object.MAX()
Example:
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->max_pt = v.max() ->print max_pt |
See also (class function)
min
Purpose
To report the maximum size of the vector. This is the maximum number of elements that can be stored in the vector.
Class
VecXYpline
Usage
{int} ret = object.MAXSIZE()
Example:
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->v = VecXYpline(5) ->v.maxsize() |
See also (class function)
size, truncate, extend
Purpose
To report the minimum x, y coordinate in the vector by searching through all poly-lines in the vector.
Class
VecXYpline
Usage
{Pt2D} ret = object.MAX()
Example:
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->min_pt = v.min() ->print min_pt |
See also (class function)
min
Purpose
To insert a poly-line, a VecPt2D object in a vector object. A new element will be insert at the last available index in the vector.
Suppose the vector has already 4 element in it, when a new element is inserted, the size is updated to 5 and the new element is stored at index number 4. The first element index is 0, and the last one is n-1, where n is no of total elements.
Class
VecXYpline
Usage
{void} object.PUSHBACK({VecPt2D} argm1)
argm1 = poly-line being inserted
Example:
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->print pline1 ->v.pushback(pline1) ->print v |
See also (class function)
init
Purpose
To find in a particular poly-line, a VecPt2D object, in a vector. Two poly-line objects are the same if their ID number are the same, thus content of poly-lines plays no roll.
This function expects that the content of the vector is already sorted, or otherwise it will not work correctly.
It performs a binary searching which is much faster than using the function "find".
The return result is an index of the vector, if found, otherwise it returns -1.
Class
VecXYpline
Usage
{int} ret = object.QFIND({VecPt2D} argm1)
argm1 = poly-line wanted to find
Example:- see class function "find"
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-> |
See also (class function)
find
Purpose
To empty the content of the vector.
This function can be used to reset the vector very quick. It simply sets the size of the vector to zero. It does not do any memory initialization.
Class
VecXYpline
Usage
{void} object.REMALL()
Example:
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->print v ->print v -> |
See also (class function)
remove
Purpose
To remove an element at a particular index out of the vector.
This function replaces the content at the required index with the last element, and simply reduces the size of the vector by 1.
Class
VecXYpline
Usage
{void} object.REMOVE({int} argm1)
argm1 = index at which the element being removed
Example:
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->print v |
See also (class function)
remall
Purpose
To reverse the order of the content of the vector. The last poly-line becomes the first element and the first poly-line becomes the last element of the vector.
Class
VecXYpline
Usage
{VecRCpline} ret = object.REVERSE()
Example:
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->print v ->print v1 |
See also (class function)
remall, remove
Purpose
To save as ASCII format. Each block in the output file represents an element, a poly-line, in the vector.
if a file name extension is not given, the function assumes an extension of ".txt".
if a path name is not include in the specified file name, the function will search in the current data path, set by command "set path".
Class
VecXYpline
Usage
{void} object.SAVE({String} argm1)
argm1 = output file name
Example:
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->v.save("my_data") |
See also (class function)
load
Purpose
To report the current size of the vector. This is the current number of elements in the vector.
Class
VecXYpline
Usage
{int} ret = object.SIZE()
Example:
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->v = VecXYpline(5) ->v.size() |
See also (class function)
maxsize, truncate, extend
Purpose
To smooth all poly-lines in the vector.
The algorithm used here is Douglas-Peucker.
The user is required to provide a tolerant distance, which is used to determine whether a vertex will be include in the smooth version of the line. A vertex is discarded if the distance from it to the line is less than the given tolerance.
Class
VecXYpline
Usage
{VecXYpline} ret = object.SMOOTH({double} argm1)
argm1 = tolerant distance (in pixel unit)
Example:
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->print v ->print v1 |
See also (class function)
Purpose
To sort poly-lines in a vector. Poly-lines are sorted from minimum to maximum according to their ID.
Class
VecXYpline
Usage
{VecXYpline} ret = object.SORT()
Example:
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->v2 =
v1.sort() |
See also (class function)
qfind
Purpose
To trim out all the empty space of the current vector.
Suppose a vector has 5 elements in it, and its max size is 500, once it is trimmed, the max size is reduced to 5. This function does a new memory initialization.
Class
VecXYpline
Usage
{void} object.TRUNCATE()
argm1 = number of elements wanted to extend
Example:
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->v = VecXYpline(5) ->v.maxsize() ->v.maxsize() |
See also (class function)
maxsize, extend
Purpose
To get the last poly-line from the vector, as well as remove it from the vector. Hence the size of the vector, the calling object, gets reduced by 1.
Class
VecXYpline
Usage
{VecPt2D} ret = object.UNSTACK()
Example:
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->print v ->print pline1 1 -> |
See also (class function)
Purpose
To extract a portion of a vector, specified by a starting index and ending index.
Class
VecXYpline
Usage
{VecXYpline} ret = object.WINDOW({int} argm1,{int} argm2)
argm1 = start index at which the element being extracted
argm2 = ending index at which the element being extracted
Example:
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->print v ->print v1 |
See also (class function)
last, unstack
Purpose
To extract poly-lines that are within the region of a specified window
Class
VecXYpline
Usage
{VecRCpline} ret = object.WINDOW_XY({double} argm1,{double} argm2, {double} argm3,{double} argm4)
argm1 = x coordinate of the lower left corner of the window
argm2 = y coordinate of the lower left corner of the window
argm3 = x coordinate of the upper right corner of the window
argm4 = y coordinate of the upper right corner of the window
Example:
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->v2 =
v1.window_xy(10,10,250,250) |
See also (class function)
window