IntStream.iterate(0, i -> i + chunkSize)
.limit((long) Math.ceil((double) input.length / chunkSize))
.mapToObj(j -> Arrays.copyOfRange(input, j, j + chunkSize > input.length ? input.length : j + chunkSize))
.collect(Collectors.toList(ArrayList<int[]>::new));
}
I was trying to print array using Java 8 stream and it should return the type List<int[]> to the main function. example input are mentioned in the code.
The code is trying to create a List<int[]>, but the syntax used to create the list is incorrect. To fix this, you can replace the following line:
.collect(Collectors.toList(ArrayList<int[]>::new));
with this line:
.collect(Collectors.toList());
This will create a List<int[]> using the default List implementation, which is ArrayList.
Alternatively, you could specify the ArrayList implementation explicitly, like this:
.collect(Collectors.toCollection(ArrayList::new));
This will also create a List<int[]> using the ArrayList implementation.
Related
My ultimate goal is to write a file of image data and the time it was taken, for multiple times. This could be used to produce time vs intensity plots.
To do this, I am trying to write a 1D image to a file stream repeatedly in time using the ImageWriteImageDataToStream() function. I go about this by attaching a Listener object to the camera view I am reading out and this listener executes a function that writes the image to a file stream using ImageWriteImageDataToStream() every time the data changes (messagemap = "data_changed:MyFunctiontoExecute") .
My question is, is there a way to also write a time stamp to this same file stream?
All I can find is StreamWriteAsText(), which takes a String data type. Can I convert time which is a Number type to a String type?
Does anyone have a better way to do this?
My solution at the moment is to create a separate file at the same time and record the timing using WriteFile(), so not using a file stream.
//MyFunctiontoExecute, where Img is the 1D image at the current time
My_file_stream.StreamSetPos(2,0)
ImageWriteImageDataToStream(Img, My_file_stream, 0)
//Write the time to the same file
Number tmp_time = GetHighResTickCount() - start_time
My_file_stream.StreamSetPos(2,0)
My_file_stream.StreamWriteAsText(0,tmp_time) //does not work
//instead using a different file
WriteFile(My_extrafileID,tmp_time+"/n")
I think your concept of streaming is wrong. When you stream to a file, at the end of the toStream() commands, the stream-position is already at the end. So you don't set the position.
Your script essentially tells the computer to set the stream back to that starting position and then to write the text - overwriting the data.
You only need the 'StreamSetPos()' command when you want to jump over some sections during reading (useful when defining import-scripts for specific file formats, for example. Or to extract only specific sub-sets from a file.).
If all you want to do is "stream-out some raw-data", you do exactly that: Just call the commands after each other:
void WriteDataPlusDateToStream( object fStream, image img, string dateStr )
{
number endian = 0
number encoding = 0
img.ImageWriteImageDataToStream(fStream,endian)
fStream.StreamWriteAsText(encoding,dateStr)
}
Similarly, you just "stream-in" by just following the same sequence:
void ReadDataPlusDateFromStream( object fStream, image img, string &dateStr )
{
number endian = 0
number encoding = 0
img.ImageReadImageDataFromStream(fStream,endian)
fStream.StreamReadTextLine(encoding,dateStr)
}
Two things are important here:
in ImageReadImageDataFromStream it is the size and data-type of the image img which defines how many bytes are read from the stream and how they are interpreted. Therefore img must have been pre-created and of fitting size and file-type.
in StreamReadTextLine the stream will continue to read in as text until it encounters the end-of-line character (\n) or the end of the stream. Therefore make sure to write this end-of-line character when streaming-out. Alternatively, you can make sure that the strings are always of a specific size and then use StreamReadAsText with the appropriate length specified.
Using the two methods above, you can use the following test-script as a starting point:
void WriteDataPlusDateToStream( object fStream, image img, string dateStr )
{
number endian = 0
number encoding = 0
img.ImageWriteImageDataToStream(fStream,endian)
fStream.StreamWriteAsText(encoding,dateStr)
}
void ReadDataPlusDateFromStream( object fStream, image img, string &dateStr )
{
number endian = 0
number encoding = 0
img.ImageReadImageDataFromStream(fStream,endian)
fStream.StreamReadTextLine(encoding,dateStr)
}
void writeTest(string path)
{
Result("\n Writing to :" + path )
image testImg := RealImage("Test",4,100)
string dateStr;
number loop = 5;
number doAutoClose = 1
object fStream = NewStreamFromFileReference( CreateFileForWriting(path), doAutoClose )
for( number i=0; i<loop; i++ )
{
testImg = icol * random()
dateStr = GetDate(1)+"#"+GetTime(1)+"|"+Format(GetHighResTickCount(),"%.f") + "\n"
fStream.WriteDataPlusDateToStream(testImg,dateStr)
sleep(0.33)
}
}
void readTest(string path)
{
Result("\n Reading form :" + path )
image testImg := RealImage("Test",4,100)
string dateStr;
number doAutoClose = 1
object fStream = NewStreamFromFileReference( OpenFileForReading(path), doAutoClose )
while ( fStream.StreamGetPos() < fStream.StreamGetSize() )
{
fStream.ReadDataPlusDateFromStream(testImg,dateStr)
result("\n time:"+dateStr)
testImg.ImageClone().ShowImage()
}
}
string path = "C:/test.dat"
ClearResults()
writeTest(path)
readTest(path)
Note, that when streaming "binary data" like this, it is you who defines the file-format. You must make sure that the writing and reading code matches up.
I get an error when using forNonBlank in OpenRefine's Templating Export feature.
I have cells with multiple subjects that I want to capture in separate dcterms:subject xml elements. Example:
Geology--Alberta--Coal Valley. // Geology, Structural. // Geology, Stratigraphic--Cretaceous.
I am using OpenRefine's Templating Export option to export to XML, similarly to the process described here.
This expression works fine:
{{forEach(cells["dcterms:subject"].value.split(" // "), v, "<dcterms:subject>" + v + "</dcterms:subject>\n")}}
I get:
<dcterms:subject>Geology--Alberta--Coal Valley.</dcterms:subject>
<dcterms:subject>Geology, Structural.</dcterms:subject>
<dcterms:subject>Geology, Stratigraphic--Cretaceous.</dcterms:subject>
But when using forNonBlank as in:
{{forNonBlank(cells["dcterms:subject"].value.split(" // "), v, "<dcterms:subject>" + v + "</dcterms:subject>\n", "")}}
I get:
<dcterms:subject>[Ljava.lang.String;#16657412</dcterms:subject>
Is there something wrong with my coding, or is this a bug?
Thanks for your help.
forNonBlank isn't an iterative function, so the function:
forNonBlank(cells["dcterms:subject"].value.split(" // "), v, "" + v + "\n", "")
Evaluates the array created through the split as to whether it is blank or not (the whole array, not each item in the array) and finding that it is not blank assigns the array to variable 'v'.
Essentially 'forNonBlank' is doing something similar to combining 'if' and 'isNonBlank', not 'forEach' and 'isNonBlank'
You've got several options for doing what you want, but you need to have an iterator in there somewhere. For example:
forEach(cells["dcterms:subject"].value.split(" // "),v,forNonBlank(v,w, "" + w + "", "")).join("/n")
I may have missed this, but is there a built-in method for serializing/deserializing lua tables to text files and vice versa?
I had a pair of methods in place to do this on a lua table with fixed format (e.g. 3 columns of data with 5 rows).
Is there a way to do this on lua tables with any arbitrary format?
For an example, given this lua table:
local scenes={
{name="scnSplash",
obj={
{
name="bg",
type="background",
path="scnSplash_bg.png",
},
{
name="bird",
type="image",
path="scnSplash_bird.png",
x=0,
y=682,
},
}
},
}
It would be converted into text like this:
{name="scnSplash",obj={{name="bg",type="background",path="scnSplash_bg.png",},{name="bird", type="image",path="scnSplash_bird.png",x=0,y=682,}},}
The format of the serialized text can be defined in any way, as long as the text string can be deserialized into an empty lua table.
I'm not sure why JSON library was marked as the right answer as it seems to be very limited in serializing "lua tables with any arbitrary format". It doesn't handle boolean/table/function values as keys and doesn't handle circular references. Shared references are not serialized as shared and math.huge values are not serialized correctly on Windows. I realize that most of these are JSON limitations (and hence implemented this way in the library), but this was proposed as a solution for generic Lua table serialization (which it is not).
One would be better off by using one of the implementations from TableSerialization page or my Serpent serializer and pretty-printer.
Lua alone doesn't have any such builtin, but implementing one is not difficult. A number of prebaked implementations are listed here: http://lua-users.org/wiki/TableSerialization
require "json"
local t = json.decode( jsonFile( "sample.json" ) )
reference here for a simple json serializer.
Add json.lua from rxi/json.lua to your project, then use it with:
local json = require("json")
local encoded = json.encode({
name = "J. Doe",
age = 42
})
local decoded = json.decode(encoded)
print(decoded.name)
Note that the code chokes if there are functions in the value you are trying to serialize. You have to fix line 82 and 93 in the code to skip values that have the function type.
Small solution: The key can be done without brackets, but be sure that here is no minuses or other special symbols.
local nl = string.char(10) -- newline
function serialize_list (tabl, indent)
indent = indent and (indent.." ") or ""
local str = ''
str = str .. indent.."{"..nl
for key, value in pairs (tabl) do
local pr = (type(key)=="string") and ('["'..key..'"]=') or ""
if type (value) == "table" then
str = str..pr..serialize_list (value, indent)
elseif type (value) == "string" then
str = str..indent..pr..'"'..tostring(value)..'",'..nl
else
str = str..indent..pr..tostring(value)..','..nl
end
end
str = str .. indent.."},"..nl
return str
end
local str = serialize_list(tables)
print(str)
I made a class and in one of its methods I needed to calculate the distance between two points. So I wrote an ordinary function named "remoteness" to do this for me.
Compilation Error:
At compilation, "remoteness" was
determined to be a variable and this
variable is uninitialized.
"remoteness" is also a function name
and previous versions of MATLAB would
have called the function.
However, MATLAB 7 forbids the use of the same name in the same context as both a function and a variable.
Error in ==> TRobot>TRobot.makeVisibilityGraph at 58
obj.visiblityGraph(k,k+1) = remoteness(:,obj.VGVertices(k),obj.VGVertices(:,k+1));
I thought the name remoteness might be a name of another function, but when I changed its name to kamran the error persisted. It should be noted that I can use the kamran function (or remoteness) in the command line without any problem.
Command line example:
>> kamran([0,0],[3,4])
ans = 5
The code of the kamran function is in a separate m file.
Code for kamran function:
function dist = kamran(v1,v2)
dist = sqrt( (v1(1) - v2(1)) ^2 + (v1(2) - v2(2)) ^2 );
Code example for how kamran function is used:
function obj = makeVisibilityGraph(obj)
verticesNumber = 0;
for num = 1: size(obj.staticObstacle,2)
verticesNumber = verticesNumber + size(obj.staticObstacle(num).polygon,2);
end
% in the below line, 2 is for start and goal vertices
obj.visibilityGraph = ones(2 + size(obj.VGVertices,2)) * Inf;
for j=1 : size(obj.staticObstacle,2)
index = size(obj.VGVertices,2);
obj.VGVertices = [obj.VGVertices, obj.staticObstacle(j).polygon];
obj.labelVGVertices = [obj.labelVGVertices, ones(1,size(obj.staticObstacle(j).polygon,2))* j ];
for k = index+1 : (size(obj.VGVertices,2)-1)
obj.visiblityGraph(k,k+1) = kamran(:,obj.VGVertices(k),obj.VGVertices(:,k+1));
end
% as the first and last point of a polygon are visible to each
% other, so set them visible to each other
obj.visibilityGraph(index+1,size(obj.VGVertices,2)) = ...
kamran( obj.VGVertices(:,index+1), obj.VGVertices(:,size(obj.VGVertices,2)));
end
end
You seem to be trying to use kamran as an array:
kamran(:,obj.VGVertices(k),obj.VGVertices(:,k+1));
Notice the first parameter ":"?
I would bet MATLAB assumes that kamran (as called here) should be a 3-dimensional array, and you are trying to select the subset containing
kamran(all-of-first-index, Nth-of-second, Mth-of-third)
The second invocation of kamran looks right:
kamran( obj.VGVertices(:,index+1), obj.VGVertices(:,size(obj.VGVertices,2))
I do not know MATLAB but I notice on this line, you are running kamran with what looks like 3 arguments. In all other cases, it is executed with 2 arguments. Maybe there is something to that?
kamran(:,obj.VGVertices(k),obj.VGVertices(:,k+1));
I have a Java array such as:
String[] arr = new String[] {"123","doc","projectReport.doc"};
In my opinion the natural way to access would be:
#set($att_id = $arr[0])
#set($att_type = $arr[1])
#set($att_name = $arr[2])
But that it is not working. I have come with this workaround. But it a bit too much code for such an easy task.
#set($counter = 0)
#foreach($el in $arr)
#if($counter==0)
#set($att_id = $el)
#elseif($counter==1)
#set($att_type = $el)
#elseif($counter==2)
#set($att_name = $el)
#end
#set($counter = $counter + 1)
#end
Is there any other way?
You can use use Velocity 1.6: for an array named $array one can simply do $array.get($index).
In the upcoming Velocity 1.7, one will be able to do $array[$index] (as well as $list[$index] and $map[$key]).
You could wrap the array in a List using Arrays.asList(T... a). The new List object is backed by the original array so it doesn't wastefully allocate a copy. Even changes made to the new List will propagate back to the array.
Then you can use $list.get(int index) to get your objects out in Velocity.
If you need to get just one or two objects from an array, you can also use Array.get(Object array, int index)
to get an item from an array.
String[] arr = new String[] {"123", "doc", "projectReport.doc"};
In my opinion the natural way to access would be:
#set($att_id = $arr[0])
#set($att_type = $arr[1])
#set($att_name = $arr[2])
The value for this can be get by using $array.get("arr", 1) because there is no direct way to get the value from array like $att_id = $arr[0] in velocity.
Hope it works :)
Velocity 1.6
$myarray.isEmpty()
$myarray.size()
$myarray.get(2)
$myarray.set(1, 'test')
http://velocity.apache.org/engine/1.7/user-guide.html
there is an implicit counter $velocityCount which starts with value 1 so you do not have to create your own counter.
Brian's answer is indeed correct, although you might like to know that upcoming Velocity 1.6 has direct support for arrays; see the Velocity documentation for more information.
I ended up using the ListTool from the velocity-tools.jar. It has methods to access an array's elements and also get its size.
I has the same question and it got answered on another thread
#set ( $Page = $additionalParams.get('Page') )
#set ( $Pages = [] )
#if ( $Page != $null && $Page != "" )
#foreach($i in $Page.split(";"))
$Pages.add($i)
#end
#end
Array indexing in Confluence / Velocity templates