Dear Tony,
Thank you for pointing this out. Worked like a charm and the distance were
calculated just fine.
Thanks,
Don
On Wednesday, July 2, 2014 9:46:06 PM UTC-4, Tony Kelman wrote:
>
> If you know all of the data in the csv file is numerical, you can provide
> a result type to readcsv, say readcsv("ct_coord.csv", Float64). See
> help(readdlm) for additional options for things like removing header rows,
> etc. If the data is of mixed types, then you may find readtable in the
> DataFrames package more capable.
>
>
> On Wednesday, July 2, 2014 5:05:21 PM UTC-7, Donald Lacombe wrote:
>>
>> Actually, another issue with the type information.
>>
>> Instead of using random coordinates, I used actual latitude and longitude
>> coordinates from a CSV file like so:
>>
>> data = readcsv("ct_coord.csv");
>>
>> temp = [xc';yc']
>>
>> 2x8 Array{Any,2}:
>>
>> -73.3712 -72.1065 -73.2453 -71.9876 … -72.7328 -72.5231 -72.8999
>>
>> 41.225 41.4667 41.7925 41.83 41.8064 41.4354 41.3488
>>
>>
>> Now, the type here is {Any,2} and this seems to be giving the Distance
>> package problems:
>>
>>
>>
>> R = pairwise(Euclidean(),temp)
>>
>> MethodError(fptype,(Any,))
>>
>>
>> Julia seems to be unhappy with this type but I'm not sure how to correct
>> this which would seem to require that the data being read in are of Float
>> type.
>>
>>
>> Again, thank you for all of the help.
>>
>>
>> Don
>>
>>
>>
>> On Wednesday, July 2, 2014 7:10:09 PM UTC-4, Donald Lacombe wrote:
>>>
>>> Patrick,
>>>
>>> Thank you for the reply! I will try your suggestion and hopefully get a
>>> better grasp of these issues.
>>>
>>> Thank you all gain for all of the help. It cannot be stressed enough
>>> that the friendly and truly helpful comments will help the Julia community
>>> grow.
>>>
>>> Don
>>>
>>> On Wednesday, July 2, 2014 5:31:55 PM UTC-4, Patrick O'Leary wrote:
>>>>
>>>> The second parameter to the Array type is the number of dimensions of
>>>> the array. "Row vectors" are implemented with 2-dimensional arrays
>>>> (a.k.a.,
>>>> "matrices"), since Vectors (a.k.a. Array{T, 1} for all types T) are
>>>> interpreted as columns.
>>>>
>>>> Since pairwise() generates all of the distances simultaneously, you'll
>>>> need to slice its results to use it in sortperm(), following your original
>>>> loop implementation. Each slice will need to be a Vector. If you slice
>>>> columns, you get Vector slices for free. If you slice rows, the shape will
>>>> be maintained, so you get a row back. You can flatten this to a Vector
>>>> with
>>>> the vec() function.
>>>>
>>>> Hope this helps!
>>>>
>>>> On Wednesday, July 2, 2014 4:23:52 PM UTC-5, Donald Lacombe wrote:
>>>>>
>>>>> After thinking about this issue, another couple of question came to
>>>>> mind.
>>>>>
>>>>> When I create a row vector, say xc = randn(1,5), the results indicate
>>>>> that the vector is e.g.
>>>>>
>>>>> xc = rand(1,5)
>>>>>
>>>>> 1x5 Array{Float64,2}:
>>>>>
>>>>> 0.989421 0.718148 0.499914 0.13024 0.939856
>>>>>
>>>>>
>>>>> The type is {Float64,2}.
>>>>>
>>>>>
>>>>> Questions:
>>>>>
>>>>>
>>>>> 1) What does the "2" mean in {Float64,2}? If I create xc = rand(5) the
>>>>> type is {Float64,1}.
>>>>>
>>>>>
>>>>> 2) The sortperm function only seems to accept {Float64,1} types. The
>>>>> Euclidean distance code create types of {Float64,2} but I need
>>>>> {Float64,1} for the sortperm function. Do I need to convert these before
>>>>> using this command?
>>>>>
>>>>>
>>>>> I'm probably missing something really basic so apologies for the query.
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Don
>>>>>
>>>>>
>>>>> On Wednesday, July 2, 2014 4:20:55 PM UTC-4, Donald Lacombe wrote:
>>>>>>
>>>>>> Greetings, part 2...
>>>>>>
>>>>>> After doing some tests, I found that this code works just fine:
>>>>>>
>>>>>> julia> using Distance
>>>>>>
>>>>>> Warning: could not import Base.foldl into NumericExtensions
>>>>>>
>>>>>> Warning: could not import Base.foldr into NumericExtensions
>>>>>>
>>>>>> Warning: could not import Base.sum! into NumericExtensions
>>>>>>
>>>>>> Warning: could not import Base.maximum! into NumericExtensions
>>>>>>
>>>>>> Warning: could not import Base.minimum! into NumericExtensions
>>>>>>
>>>>>>
>>>>>>
>>>>>> julia> xc = rand(8)'
>>>>>>
>>>>>> 1x8 Array{Float64,2}:
>>>>>>
>>>>>> 0.30107 0.479169 0.230607 0.65126 0.386921 0.455316 0.921496
>>>>>> 0.244873
>>>>>>
>>>>>>
>>>>>> julia> yc = rand(8)'
>>>>>>
>>>>>> 1x8 Array{Float64,2}:
>>>>>>
>>>>>> 0.866199 0.767794 0.76163 0.262925 … 0.742765 0.980952 0.424966
>>>>>>
>>>>>>
>>>>>> julia> temp = [xc ; yc]
>>>>>>
>>>>>> 2x8 Array{Float64,2}:
>>>>>>
>>>>>> 0.30107 0.479169 0.230607 0.65126 … 0.455316 0.921496 0.244873
>>>>>>
>>>>>> 0.866199 0.767794 0.76163 0.262925 0.742765 0.980952 0.424966
>>>>>>
>>>>>>
>>>>>> julia> R = pairwise(Euclidean(),temp)
>>>>>>
>>>>>> 8x8 Array{Float64,2}:
>>>>>>
>>>>>> 0.0 0.203477 0.126094 0.697548 … 0.197554 0.630949
>>>>>> 0.444797
>>>>>>
>>>>>> 0.203477 0.0 0.248638 0.533393 0.0345751 0.491009
>>>>>> 0.415241
>>>>>>
>>>>>> 0.126094 0.248638 0.0 0.652423 0.225499 0.724865
>>>>>> 0.336966
>>>>>>
>>>>>> 0.697548 0.533393 0.652423 0.0 0.518306 0.767196
>>>>>> 0.437502
>>>>>>
>>>>>> 0.376201 0.283308 0.304834 0.355027 0.252287 0.719136
>>>>>> 0.160613
>>>>>>
>>>>>> 0.197554 0.0345751 0.225499 0.518306 … 0.0 0.523505
>>>>>> 0.381159
>>>>>>
>>>>>> 0.630949 0.491009 0.724865 0.767196 0.523505 0.0
>>>>>> 0.87575
>>>>>>
>>>>>> 0.444797 0.415241 0.336966 0.437502 0.381159 0.87575 0.0
>>>>>>
>>>>>>
>>>>>>
>>>>>> As expected, the diagonal elements are 0 and everything seems to work
>>>>>> fine although I did not test other distance formulas.
>>>>>>
>>>>>> I'm posing this so others can see the results and possibly make use
>>>>>> of this themselves.
>>>>>>
>>>>>> Is there a central repository for user submitted solutions or
>>>>>> examples? If so I'd like to post this so others can see or alternatively
>>>>>> someone else is free to use this (and the original code I posted) for
>>>>>> future reference.
>>>>>>
>>>>>> Thank you all again for your help! I'm going to be coding some models
>>>>>> this summer and will probably be back to bug everyone again.
>>>>>>
>>>>>> Thanks,
>>>>>> Don
>>>>>>
>>>>>> On Wednesday, July 2, 2014 10:22:58 AM UTC-4, Donald Lacombe wrote:
>>>>>>>
>>>>>>> Greetings!
>>>>>>>
>>>>>>> I am a new Julia user and have the following issue. I am writing
>>>>>>> code to calculate a knn spatial weight matrix to estimate a spatial
>>>>>>> econometric model. Using the MATLAB code from Jim LeSage's Econometrics
>>>>>>> Toolbox, I converted that code into Julia as follows:
>>>>>>>
>>>>>>> xc = rand(8);
>>>>>>>
>>>>>>> yc = rand(8);
>>>>>>>
>>>>>>> n = length(xc);
>>>>>>>
>>>>>>> k = 2;
>>>>>>>
>>>>>>> distance = zeros(n);
>>>>>>>
>>>>>>> nnlist = zeros(n,k);
>>>>>>>
>>>>>>> tempw = zeros(n,n);
>>>>>>>
>>>>>>>
>>>>>>> for i=1:n;
>>>>>>>
>>>>>>> xi = xc[i,1];
>>>>>>>
>>>>>>> yi = yc[i,1];
>>>>>>>
>>>>>>> distance = (xc - xi*ones(n)).^2 + (yc - yi*ones(n)).^2
>>>>>>>
>>>>>>> temp = sortperm(distance)
>>>>>>>
>>>>>>> nnlist[i,1:k] = temp[2:k+1,1]';
>>>>>>>
>>>>>>> end
>>>>>>>
>>>>>>>
>>>>>>> for i=1:n
>>>>>>>
>>>>>>> tempw[i,nnlist[i,:]] = 1;
>>>>>>>
>>>>>>> end
>>>>>>>
>>>>>>>
>>>>>>> W = tempw/k;
>>>>>>>
>>>>>>>
>>>>>>> This is a "toy" example and I was wondering if I can use the Distance
>>>>>>> package to simplify the distance = (xc - xi*ones(n)).^2 + (yc -
>>>>>>> yi*ones(n)).^2 formula. I tried using the pairwise option like so:
>>>>>>>
>>>>>>>
>>>>>>> R = pairwise(Euclidean(),xc,yc) but received the following message:
>>>>>>>
>>>>>>>
>>>>>>> R = pairwise(Euclidean(),xc,yc)
>>>>>>>
>>>>>>> MethodError(pairwise,(Euclidean(),[0.05961066617957589,0.018538084399339905,0.39282193332224646,0.7006919213133509,0.5099836895629475,0.8448415935222402,0.2985674570217043,0.8022287058003177],[0.5808687231553928,0.9655167324458858,0.026306556019434435,0.6565373244339141,0.11927452074471412,0.11873635450496622,0.6271632933770979,0.7081439899673692]))
>>>>>>>
>>>>>>> I'd like to be able to utilize the Distance package but am a bit
>>>>>>> stumped. The code as written works but it's bugging me that I cannot
>>>>>>> seem to get the above command to work. I also get the following error
>>>>>>> when loading Distance:
>>>>>>>
>>>>>>>
>>>>>>> using Distance
>>>>>>>
>>>>>>> Warning: could not import Base.foldl into NumericExtensions
>>>>>>>
>>>>>>> Warning: could not import Base.foldr into NumericExtensions
>>>>>>>
>>>>>>> Warning: could not import Base.sum! into NumericExtensions
>>>>>>>
>>>>>>> Warning: could not import Base.maximum! into NumericExtensions
>>>>>>>
>>>>>>> Warning: could not import Base.minimum! into NumericExtensions
>>>>>>>
>>>>>>>
>>>>>>> If there is anyone who can address this I'd greatly appreciate it.
>>>>>>> Incidentally, the help on this group is one reason I am making the
>>>>>>> change.
>>>>>>>
>>>>>>>
>>>>>>> Don
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
