h=0.0125
nx=5395
nz=956
vel=np.fromfile("bp0.0125km.drt",dtype="float32")
vel.shape=(nx,nz)
factor=np.float32(1000.0)
print vel.max(), vel.min()

imshow(vel.T)

def plot_vel(vel,img,h,unit='km/s',tick=arange(1.5,6,1)):
    xmax=(vel.shape[0]-1)*h
    zmax=(vel.shape[1]-1)*h
    fs=14
    figure(figsize=(18,4))
    ax=imshow(vel.transpose(),extent=(0,xmax,zmax,0),cmap=cm.gray_r)
    tick_params(labelsize=fs)
    xlabel('Distance (km)',fontsize=fs)
    ylabel('Depth (km)',fontsize=fs)

    ax.axes.set_yticks(arange(0,zmax+1,3)) 
    cb=colorbar(shrink=0.68,pad=0.01,aspect=10,ticks=tick)
    clim([vel.min(),vel.max()])
    cb.set_label(unit,fontsize=fs)
    ct=getp(cb.ax,'ymajorticklabels')
    setp(ct,fontsize=fs)
    
    savefig(img)

plot_vel(vel,'BP.eps',h)

vel

def scale_py(vel,nx,nz,factor):
    scaled=empty_like(vel)
    for ix in xrange(nx):
        for iz in xrange(nz):
            scaled[ix,iz]=vel[ix,iz]*factor
    return scaled

scaled=scale_py(vel,nx,nz,factor)

scaled

plot_vel(scaled,'BP_meter.eps',h,'m/s',arange(1500,6000,1000))

%timeit -r 3 -n 3 scale_py(vel,nx,nz,factor)

def scale_np(vel,factor):
    return vel*factor

%timeit -r 3 -n 3 scale_np(vel,factor)

from numba import autojit
scale_nb=autojit(scale_py)

%timeit -r 3 -n 3 scale_nb(vel,nx,nz,factor)

%load_ext cythonmagic

%%cython
import cython
import numpy as np
cimport numpy as np

@cython.boundscheck(False)
@cython.wraparound(False)
@cython.nonecheck(False)
def scale_cy(np.ndarray[float,ndim=2] vel,int nx,int nz,float factor):
    cdef np.ndarray[float,ndim=2] scaled=np.empty_like(vel)
    cdef int ix,iz
    for ix in xrange(nx):
        for iz in xrange(nz):
            scaled[ix,iz]=vel[ix,iz]*factor
    return scaled

%timeit -r 3 -n 3 scale_cy(vel,nx,nz,factor)

%%file scale.f90

subroutine scale_f(scaled,vel,nx,nz,factor)
implicit none
integer,intent(in):: nx,nz
real,intent(in):: vel(nz,nx),factor
real,intent(out):: scaled(nz,nx)
integer iz,ix
do ix=1,nx
do iz=1,nz
    scaled(iz,ix)=vel(iz,ix)*factor
enddo
enddo
end subroutine

subroutine scale_fv(scaled,vel,nx,nz,factor)
implicit none
integer,intent(in):: nx,nz
real,intent(in):: vel(nz,nx),factor
real,intent(out):: scaled(nz,nx)
scaled=vel*factor
end subroutine

!f2py -c -m scale_f scale.f90 --f90exec=/opt/local/bin/gfortran-mp-4.9 > log.txt

import scale_f
print scale_f.__doc__

vel_t=vel.T

%timeit -r 3 -n 3 scale_f.scale_f(vel_t,factor)

%timeit -r 3 -n 3 scale_f.scale_fv(vel_t,factor)