Trouble datamining with Django - database

Question

I've set up a Django project in which i create random points. These random points are stored in a database(sqlite) (i can see them via the admin website and change the values, so this works).
If i the write a script i can access the points and print them in a plot. See code below.
But if I then want to mine these points to sort them or only plot a selection of the dataset i seem to have trouble. If i readout the values they are not connected anymore and sorting x would mix up the point set.
Is there a way to sort the data set to a minimum value of in this case X and the sort the values and print the set? (keep all x, y, z and name value of the point intact?) (see answer below, point in Point3D.objects.all().order_by('x'):)
If i now want to to have the values of x between x = 12 and x = 30? how can i add this extra filter?
My code is as follows:
models.py:
class Point3D(models.Model):
name = models.CharField(max_length = 10)
x = models.DecimalField(max_digits=5, decimal_places=2)
y = models.DecimalField(max_digits=5, decimal_places=2)
z = models.DecimalField(max_digits=5, decimal_places=2)
generate the points:
from books.models import Point3D
def points():
for i in range(20):
x = random.randint(0,100)
y = random.randint(0,100)
z = random.randint(0,100)
p = Point3D(name = x , x = x ,y = y,z = z)
# print 'test'
p.save()
#
points()
in views.py:
def ThreeGraphs(request):
fig = Figure()
fig.suptitle('2D-punten')
ax = fig.add_subplot(111)
for point in Point3D.objects.all():
print point
name = int(point.name)
xs = int(point.x)
ys = int(point.y)
zs = int(point.z)
print (xs, ys, zs)
ax.plot(xs, ys, 'bo' )
HttpResponse(mimetype="image/png")
FigureCanvas(fig)
fig.savefig('template/images/testing.png')
picture = "testing.png"
return render_to_response('Test.html', {'picture': picture}, RequestContext(request))
Hope anyone knows how to solve my trouble.
Thanks a lot!
Tijl

Answer 1

You need to to this:
for point in Point3D.objects.all().order_by('x'):
This will return the points in sorted order by the 'x' field. You can say order_by('-x') to reverse the sort order.