I know gdb has several means of exploring data, some of them quite convenient. However, I cannot combine them to get that I need/want. I would like to display some custom string based on the first n values of a big array starting at <PT_arr>, and the last m values of the same array at a distance (in this case) 4096. Looking something like this:
table beginning:
0x804cfe0 <PT_arr>: 0x00100300 0x00200300 0x00300300 0x00400300
table end:
0x804cfe0 <PT_arr+4064>: 0x00500300 0x00600300 0x00700300 0x00800300
printf let's me add custom text (like table beginning)
the examine x gives me that nice alignment, let's me read many elements and group them by byte, words, etc; and shows addresses at the left (which is ideal for my case).
x aligns the content of regions of memory in an easy to read manner with the size and unit parameters. (what I want)
display is constantly printing. (what I want).
The issue with display (manual), is that unlike examine x (manual) it doesn't have a size or unit parameter.
Is there a way to accomplish that?
Thanks.
Related
Suppose I have a long array.
> using MakieGallery
> size(database)
(210,)
If I do
> [d.title for d=database]
it will print it truncated, and if I show it, it will print it into a mess:
> show([d.title for d=database])
I don't know how, but probably I could print values into a column and it would scroll my console far up.
All this is bad. Is it possible to do some sort of simple "watch" of a variable? I.e. open some small widget in separate window with a list control, diplaying an array, which I could scroll as needed?
Internally Julia uses Base.show to display the values in the REPL, you can simply extend this function in any way you like (this example is just a really simple implementation to print every element of array in a new line and you probably shouldn't use it):
Base.show(io::IO, ::MIME"text/plain", x::Array) = x .|> println
You can then go on and add your function to .julia/config/startup.jl to load this every time you start the REPL. Just make sure to have a really solid implementation to handle various edge cases where it might not function properly.
Pluto.jl has a very nice viewer for tabular data (including arrays). It truncats the output per default, but offers a button to show more.
Furthermore, the view automatically updates when you change the data in another cell.
I'm new to AMPL and I have data in a text file in matrix form from which I need to use certain values. However, I don't know how to use the matrices directly without having to manually add column and row indexes to them. Is there a way around this?
So the data I need to use looks something like this, with hundreds of rows and columns (and several more matrices like this), and I would like to use it as a parameter with index i for rows and j for columns.
t=1
0.0 40.95 40.36 38.14 44.87 29.7 26.85 28.61 29.73 39.15 41.49 32.37 33.13 59.63 38.72 42.34 40.59 33.77 44.69 38.14 33.45 47.27 38.93 56.43 44.74 35.38 58.27 31.57 55.76 35.83 51.01 59.29 39.11 30.91 58.24 52.83 42.65 32.25 41.13 41.88 46.94 30.72 46.69 55.5 45.15 42.28 47.86 54.6 42.25 48.57 32.83 37.52 58.18 46.27 43.98 33.43 39.41 34.0 57.23 32.98 33.4 47.8 40.36 53.84 51.66 47.76 30.95 50.34 ...
I'm not aware of an easy way to do this. The closest thing is probably the table format given in section 9.3 of the AMPL Book. This avoids needing to give indices for every term individually, but it still requires explicitly stating row and column indices.
AMPL doesn't seem to do a lot with position-based input formats, probably because it defaults to treating index sets as unordered so the concept of "first row" etc. isn't meaningful.
If you really wanted to do it within AMPL, you could probably put together a work-around along these lines:
declare a single-index param with length equal to the total size of your matrix (e.g. if your matrix is 10 x 100, this param has length 1000)
edit the beginning and end of your "matrix" data file to turn it into appropriate format for a single-index parameter indexed from 1 to n
then define your matrix something like this:
param m{i in 1..nrows,j in 1..ncols} := x[j+i*(ncols-1)];
(not tested, I won't promise that I have rows and columns the right way around there!)
But you're probably better off editing the input file into one of the standard AMPL matrix formats. AMPL isn't really designed for data wrangling - you can do it in a pinch but if you're doing this kind of thing repeatedly it may be less trouble to code it in a general-purpose language e.g. Python.
If you have a statically allocated array, the Visual Studio debugger can easily display all of the array elements. However, if you have an array allocated dynamically and pointed to by a pointer, it will only display the first element of the array when you click the + to expand it. Is there an easy way to tell the debugger, show me this data as an array of type Foo and size X?
Yes, simple.
say you have
char *a = new char[10];
writing in the debugger:
a,10
would show you the content as if it were an array.
There are two methods to view data in an array m4x4:
float m4x4[16]={
1.f,0.f,0.f,0.f,
0.f,2.f,0.f,0.f,
0.f,0.f,3.f,0.f,
0.f,0.f,0.f,4.f
};
One way is with a Watch window (Debug/Windows/Watch). Add watch =
m4x4,16
This displays data in a list:
Another way is with a Memory window (Debug/Windows/Memory). Specify a memory start address =
m4x4
This displays data in a table, which is better for two and three dimensional matrices:
Right-click on the Memory window to determine how the binary data is visualized. Choices are limited to integers, floats and some text encodings.
In a watch window, add a comma after the name of the array, and the amount of items you want to be displayed.
a revisit:
let's assume you have a below pointer:
double ** a; // assume 5*10
then you can write below in Visual Studio debug watch:
(double(*)[10]) a[0],5
which will cast it into an array like below, and you can view all contents in one go.
double[5][10] a;
For,
int **a; //row x col
add this to watch
(int(**)[col])a,row
Yet another way to do this is specified here in MSDN.
In short, you can display a character array as several types of string. If you've got an array declared as:
char *a = new char[10];
You could print it as a unicode string in the watch window with the following:
a,su
See the tables on the MSDN page for all of the different conversions possible since there are quite a few. Many different string variants, variants to print individual items in the array, etc.
You can find a list of many things you can do with variables in the watch window in this gem in the docs:
https://msdn.microsoft.com/en-us/library/75w45ekt.aspx
For a variable a, there are the things already mentioned in other answers like
a,10
a,su
but there's a whole lot of other specifiers for format and size, like:
a,en (shows an enum value by name instead of the number)
a,mb (to show 1 line of 'memory' view right there in the watch window)
For MFC arrays (CArray, CStringArray, ...)
following the next link in its Tip #4
http://www.codeproject.com/Articles/469416/10-More-Visual-Studio-Debugging-Tips-for-Native-De
For example for "CArray pArray", add in the Watch windows
pArray.m_pData,5
to see the first 5 elements .
If pArray is a two dimensional CArray you can look at any of the elements of the second dimension using the next syntax:
pArray.m_pData[x].m_pData,y
I haven't found a way to use this with a multidimensional array. But you can at least (if you know the index of your desired entry) add a watch to a specific value. Simply use the index-operator.
For an Array named current, which has an Array named Attribs inside, which has an Array named Attrib inside, it should look like this if you like to have to position 26:
((*((*current).Attribs)).Attrib)[26]
You can also use an offset
((*((*current).Attribs)).Attrib)+25
will show ne "next" 25 elements.
(I'm using VS2008, this shows only 25 elements maximum).
I am trying to reduce the size of my data and I cannot make it work. I have data points taken every minute over 1 month. I want to reduce this data to have one sample for every hour. The problem is: Some of my runs have "NA" value, so I delete these rows. There is not exactly 60 points for every hour - it varies.
I have a 'Timestamp' column. I have used this to make a 'datehour' column which has the same value if the data set has the same date and hour. I want to average all the values with the same 'datehour' value.
How can I do this? I have tried using the if and for loop below, but it takes so long to run.
Thanks for all your help! I am new to Julia and come from a Matlab background.
======= CODE ==========
uniquedatehour=unique(datehour,1)
index=[]
avedata=reshape([],0,length(alldata[1,:]))
for j in uniquedatehour
for i in 1:length(datehour)
if datehour[i]==j
index=vcat(index,i)
else
rows=alldata[index,:]
rows=convert(Array{Float64,2},rows)
avehour=mean(rows,1)
avedata=vcat(avedata,avehour)
index=[]
continue
end
end
end
There are several layers to optimizing this code. I am assuming that your data is sorted on datehour (your code assumes this).
Layer one: general recommendation
Wrap your code in a function. Executing code in global scope in Julia is much slower than within a function. By wrapping it make sure to either pass data to your function as arguments or if data is in global scope it should be qualified with const;
Layer two: recommendations to your algorithm
Statement like [] creates an array of type Any which is slow, you should use type qualifier like index=Int[] to make it fast;
Using vcat like index=vcat(index,i) is inefficient, it is better to do push!(index, i) in place;
It is better to preallocate avedata with e.g. fill(NA, length(uniquedatehour), size(alldata, 2)) and assign values to an existing matrix than to do vcat on it;
Your code will produce incorrect results if I am not mistaken as it will not catch the last entry of uniquedatehour vector (assume it has only one element and check what happens - avedata will have zero rows)
Line rows=convert(Array{Float64,2},rows) is probably not needed at all. If alldata is not Matrix{Float64} it is better to convert it at the beginning with Matrix{Float64}(alldata);
You can change line rows=alldata[index,:] to a view like view(alldata, index, :) to avoid allocation;
In general you can avoid creation of index vector as it is enough that you remember start s and end e position of the range of the same values and then use range s:e to select rows you want.
If you correct those things please post your updated code and maybe I can help further as there is still room for improvement but requires a bit different algorithmic approach (but maybe you will prefer option below for simplicity).
Layer three: how I would do it
I would use DataFrames package to handle this problem like this:
using DataFrames
df = DataFrame(alldata) # assuming alldata is Matrix{Float64}, otherwise convert it here
df[:grouping] = datehour
agg = aggregate(df, :grouping, mean) # maybe this is all what you need if DataFrame is OK for you
Matrix(agg[2:end]) # here is how you can convert DataFrame back to a matrix
This is not the fastest solution (as it converts to a DataFrame and back but it is much simpler for me).
I've been playing around with a .lua file which passes a random phrase using the following line:
SendChatMessage(GetRandomArgument("text1", "text2", "text3", "text4"), "RAID")
My problem is that I have a lot of phrases and the one line of code is very long indeed.
Is there a way to hold
text1
text2
text3
text3
in a list somewhere else in the code (or externally) and call a random value from the main code. Would make maintaining the list of text options easier.
For lists up to a few hundred elements, then the following will work:
messages = {
"text1",
"text2",
"text3",
"text4",
-- ...
}
SendChatMessage(GetRandomArgument(unpack(messages)), "RAID")
For longer lists, you would be well served to replace GetRandomArgument with GetRandomElement that would take a single table as its argument and return a random entry from the table.
Edit: Olle's answer shows one way that something like GetRandomElement might be implemented. But it used table.getn on every call which is deprecated in Lua 5.1, and its replacement (table.maxn) has a runtime cost proportional to the number of elements in the table.
The function table.maxn is only required if the table in use might have missing elements in its array part. However, in this case of a list of items to choose among, there is likely to be no reason to need to allow holes in the list. If you need to edit the list at run time, you can always use table.remove to remove an item since it will also close the gap.
With a guarantee of no gaps in the array of text, then you can implement GetRandomElement like this:
function GetRandomElement(a)
return a[math.random(#a)]
end
So that you send the message like this:
SendChatMessage(GetRandomElement(messages), "RAID")
You want a table to contain your phrases like
phrases = { "tex1", "text2", "text3" }
table.insert(phrases ,"text4") -- alternative syntax
SendChatMessage(phrases[math.random(table.getn(phrases))], "RAID")
Note: getn gets the size of the table; math.random gets a random number (with a max of the size of the phrases table) and the phrases[] syntax returns the table element at the index inside [].