The reason is that you typically get many datasets when loading results and the calls thus return a list

On 26 Sep 2015, at 15:22, Huaiming Guo <hmguo@buaa.edu.cn> wrote:

Dear Michele,

Thank you very much. It works now. I am a bit curious why [0] should be added. It is hard to figure it out.

 
Sincerely,
Huaiming Guo
 
发件人: comp-phys-alps-users-bounces@lists.phys.ethz.ch [mailto:comp-phys-alps-users-bounces@lists.phys.ethz.ch] 代表 Michele Dolfi
发送时间: 2015年9月26日 20:34
收件人: comp-phys-alps-users@lists.phys.ethz.ch
主题: Re: [ALPS-users] About the class DataSet
 
Dear Huaiming,
 
From the “[“ at the beginning of your output, I think that your magnetization variable is a list of DataSet objects. (maybe a list with only one entry)
This is quite common in pyalps, since most functions operate on list of datasets, and return list of datasets.
 
To access the data the following should work:
magnetization[0].x
magnetization[0].y
 
 
 
Regards,
Michele
 
--
ETH Zurich
Michele Dolfi
Institute for Theoretical Physics
HIT G 32.4
Wolfgang-Pauli-Str. 27
8093 Zurich
Switzerland
 
 
+41 44 633 78 56 phone
+41 44 633 11 15 fax 
 
On 26 Sep 2015, at 08:05, Huaiming Guo <hmguo@buaa.edu.cn> wrote:
 

Dear All,

   I have a question about the dataset class. Suppose I have a variable “magnetization” in class dataset (see below). I prefer the data form as the following,

X(1), y(1)

X(2), y(2)….

I want to know how I use the x of magnetization. I tried magnetization.x or magnetization.y, but it does not give me results. Many thanks for the reply.

 

Sincerely,

Huaiming

 

 

class DataSet(ResultProperties):

 

magnetization

[x=[ 0.   0.1  0.2  0.3  0.4  0.5  0.6  0.7  0.8  0.9  1.   1.2  1.4  1.6  1.8

  2.   2.2  2.4  2.5]

y=[0.000125981483652 +/- 0.000122322506977

 0.00860528601563 +/- 0.000365690783567

 0.0222620599739 +/- 0.00089047889358 0.0370211267606 +/- 0.000570927849528

 0.048406793936 +/- 0.000429342486559 0.0584663763909 +/- 0.0004796634673

 0.0728869134363 +/- 0.000659369158556

 0.0893286949981 +/- 0.000587776900735 0.101889483066 +/- 0.000593519471563

 0.1160502693 +/- 0.000825142408233 0.133805849632 +/- 0.00057575130612

 0.165816585036 +/- 0.000469748080503 0.208087821355 +/- 0.000521162407847

 0.258726150393 +/- 0.000553055778572 0.331226556639 +/- 0.000601625820527

 0.434736729908 +/- 0.000675053120055 0.491099090239 +/- 0.0003387686197

 0.499313131313 +/- 8.51581569713e-05 0.499728317659 +/- 5.31002968192e-05]

props={'observable': 'Magnetization Density', 'local_S': 0.5, 'THERMALIZATION':

100.0, 'J': 1.0, 'SWEEPS': 100.0, 'L': 20.0, 'LATTICE': 'chain lattice', 'hdf5_p

ath': '/simulation/results/Magnetization Density', 'xlabel': 'h', 'T': 0.08, 'yl

abel': 'Magnetization Density', 'MODEL': 'spin', 'label': ''}]