Databases
StackOverflow2013
Postsdbo
POExponent not working normally
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POExponent not working normally
    primarykey
    data
    text
    <p>I am working in python 2.6. Can anyone figure out why my variable squared does not calculate properly when it is inside a min() function? To illustrate, I show the variable**2 performed by itself, works fine. Here is the code, followed by some results:</p> <pre><code>from __future__ import with_statement import csv, re, time timestr = time.strftime("%Y%m%d_%H%M%S") fileinput = 'mp_20130822.csv' out = open('output2.csv',"wb") writer = csv.writer(out, delimiter = ',') ESPmax = 100.00 dynmax = "enabled" def config(): global argument if z&gt;30: argument = "T" else: argument = "F" with open(fileinput,'rU') as inputfile: reader = csv.reader(inputfile, delimiter = ';') for line in reader: line = re.split(",| ",line[0]) side = str(line[4]) #is "Bid" or "Ask" e = float(line[5]) z = float(line[6]) t = float(line[33]) FW = float(line[34]) FS = max(float(line[35]),200) if FW == 0: continue if (FS == 0) or (FS == 1): continue if side == "Ask": LE = t-e else: LE = e-t LEP = LE/(FW/2) ESP = z/(FS/2) if dynmax == "enabled": ESPmax = min(LEP**2,ESPmax) config() if (argument == "T"): print ('side, e, z, t, FW, FS') print ('LEP,LEP,ESPmax') print (side, '%.2f'%e, '%.2f'%z, '%.2f'%t, '%.2f'%FW, '%.2f'%FS) print ('%.3f'%LEP,'%.3f'%LEP,'%.5f'%ESPmax) print '%.5f'%(LEP*LEP) </code></pre> <p>RESULTS:</p> <pre><code>side, e, z, t, FW, FS LEP,LEP,ESPmax ('Ask', '1.90', '50.00', '1.95', '0.24', '651.00') ('0.423', '0.423', '0.00130') 0.17880 side, e, z, t, FW, FS LEP,LEP,ESPmax ('Ask', '8.40', '40.00', '8.43', '0.17', '4933.00') ('0.348', '0.348', '0.00130') 0.12145 side, e, z, t, FW, FS LEP,LEP,ESPmax ('Ask', '8.40', '40.00', '8.43', '0.17', '4919.00') ('0.370', '0.370', '0.00130') 0.13667 </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USteachamantofish
    1. USteachamantofish
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COSeems to work fine, `ESPmax = min(LEP**2,ESPmax)` seems to have set `ESPmax` to a value smaller than any of the `LEP**2` you printed out, so of course the minimum is the smaller value `0.00130` you probably got from an `LEP` of `0.036` earlier.
      singulars
      1. POExponent not working normally
      1. USDaniel Fischer
    2. COhow could ESPmax have been reduced to 0.00130?
      singulars
      1. POExponent not working normally
      1. USteachamantofish
    3. COBy an `LEP` value of approximately `0.036` earlier. Since it's extremely unlikely that `min` or `**2` don't work correctly, and you always get the same value in what you pasted here, it's overwhelmingly likely that something changed the value of `ESPmax` to `0.00130` before. Note that you only print anything if `Z > 30` (which, by the way, doesn't seem to be defined where it's used in `config()`).
      singulars
      1. POExponent not working normally
      1. USDaniel Fischer
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload