Displaying & Visualisation
==========================
Printing/displaying Info
-----------------------
Current info
.. code:: python
state = [0,0,0,1,0]
fpoly = [5,4,3,2]
L = LFSR(fpoly=fpoly,initstate =state, verbose=True)
L.info()
5-bit LFSR with feedback polynomial x^5 + x^4 + x^3 + x^2 + 1 with
Expected Period (if polynomial is primitive) = 31
Computing configuration is set to Fibonacci with output sequence taken from 5-th (-1) register
Current :
State : [0 0 0 1 0]
Count : 0
Output bit : -1
feedback bit : -1
::
print(L)
LFSR ( x^5 + x^4 + x^3 + x^2 + 1)
==================================================
initstate = [0 0 0 1 0]
fpoly = [5, 4, 3, 2]
conf = fibonacci
order = 5
expectedPeriod = 31
seq_bit_index = -1
count = 0
state = [0 0 0 1 0]
outbit = -1
feedbackbit = -1
seq = [-1]
counter_start_zero = True
Parameters setting
------------------
::
repr(L)
"LFSR('fpoly'=[5, 4, 3, 2], 'initstate'=[0, 0, 0, 1, 0],'conf'=fibonacci, 'seq_bit_index'=-1,'verbose'=True, 'counter_start_zero'=True)"
Visualise LFSR
-------------------
**Plotting LFSR with pylsr**
Each LFSR can be visualize as it in current state by using *.Viz()* method
::
L = LFSR(initstate=[1,1,0,1,1],fpoly=[5,2])
L.runKCycle(15)
L.Viz(title='R1')
.. image:: https://raw.githubusercontent.com/nikeshbajaj/Linear_Feedback_Shift_Register/master/images/5bit_1.jpg
Dynamic visualisation of LFSR - Animation
-----------------------------------------
::
%matplotlib notebook
L = LFSR(initstate=[1,0,1,0,1],fpoly=[5,4,3,2],counter_start_zero=False)
::
fig, ax = plt.subplots(figsize=(8,3))
for _ in range(35):
ax.clear()
L.Viz(ax=ax, title='R1')
plt.ylim([-0.1,None])
#plt.tight_layout()
L.next()
fig.canvas.draw()
plt.pause(0.1)
.. image:: https://raw.githubusercontent.com/nikeshbajaj/Linear_Feedback_Shift_Register/master/images/5bit_1.gif
Similarly other can be created as
.. image:: https://raw.githubusercontent.com/nikeshbajaj/Linear_Feedback_Shift_Register/master/images/FibanacciLFSR_2.gif
.. image:: https://raw.githubusercontent.com/nikeshbajaj/Linear_Feedback_Shift_Register/master/images/GaloisLFSR_1.gif
Show each state and each cycle
------------------------------
**Setting clock start:**
Initial output bit
An argument *counter_start_zero* can be used to initialize the output bit.
* If *counter_start_zero=True* (default), the output bit is initialize by -1, to illustrate that No clock is provided yet.
In this case, *cout* (counter) starts with 0. The first output is not computed until first cylce is executed, such as by executing .next(), .runFullCycle, etc
* If *counter_start_zero=False*, the output bit is initialize by the last bit of register. In one sense, first clock cycle is executed.
This is why, in this case, *cout* (counter) starts with 1.
In both cases counter_start_zero =True or False, the L.seq will be same, the only difference is the total number of output bits produced after N-cycles, i.e.
when setting *counter_start_zero = False*, there will be one extra bit, since first bit was already computed. To understand this, look at following two examples.
*counter_start_zero=True* can be seen as dealyed response by one bit.
Visualise 3-bit LFSR
--------------------
**At each step, with default 'counter_start_zero = True'**
::
state = [1,1,1]
fpoly = [3,2]
L = LFSR(initstate=state,fpoly=fpoly)
print('count \t state \t\toutbit \t seq')
print('-'*50)
for _ in range(15):
print(L.count,L.state,'',L.outbit,L.seq,sep='\t')
L.next()
print('-'*50)
print('Output: ',L.seq)
::
count state outbit seq
--------------------------------------------------
0 [1 1 1] -1 [-1]
1 [0 1 1] 1 [1]
2 [0 0 1] 1 [1 1]
3 [1 0 0] 1 [1 1 1]
4 [0 1 0] 0 [1 1 1 0]
5 [1 0 1] 0 [1 1 1 0 0]
6 [1 1 0] 1 [1 1 1 0 0 1]
7 [1 1 1] 0 [1 1 1 0 0 1 0]
8 [0 1 1] 1 [1 1 1 0 0 1 0 1]
9 [0 0 1] 1 [1 1 1 0 0 1 0 1 1]
10 [1 0 0] 1 [1 1 1 0 0 1 0 1 1 1]
11 [0 1 0] 0 [1 1 1 0 0 1 0 1 1 1 0]
12 [1 0 1] 0 [1 1 1 0 0 1 0 1 1 1 0 0]
13 [1 1 0] 1 [1 1 1 0 0 1 0 1 1 1 0 0 1]
14 [1 1 1] 0 [1 1 1 0 0 1 0 1 1 1 0 0 1 0]
--------------------------------------------------
Output: [1 1 1 0 0 1 0 1 1 1 0 0 1 0 1]
**At each step, with default 'counter_start_zero = False'**
::
state = [1,1,1]
fpoly = [3,2]
L = LFSR(initstate=state,fpoly=fpoly,counter_start_zero=False)
print('count \t state \t\toutbit \t seq')
print('-'*50)
for _ in range(15):
print(L.count,L.state,'',L.outbit,L.seq,sep='\t')
L.next()
print('-'*50)
print('Output: ',L.seq)
::
count state outbit seq
--------------------------------------------------
1 [1 1 1] 1 [1]
2 [0 1 1] 1 [1 1]
3 [0 0 1] 1 [1 1 1]
4 [1 0 0] 0 [1 1 1 0]
5 [0 1 0] 0 [1 1 1 0 0]
6 [1 0 1] 1 [1 1 1 0 0 1]
7 [1 1 0] 0 [1 1 1 0 0 1 0]
8 [1 1 1] 1 [1 1 1 0 0 1 0 1]
9 [0 1 1] 1 [1 1 1 0 0 1 0 1 1]
10 [0 0 1] 1 [1 1 1 0 0 1 0 1 1 1]
11 [1 0 0] 0 [1 1 1 0 0 1 0 1 1 1 0]
12 [0 1 0] 0 [1 1 1 0 0 1 0 1 1 1 0 0]
13 [1 0 1] 1 [1 1 1 0 0 1 0 1 1 1 0 0 1]
14 [1 1 0] 0 [1 1 1 0 0 1 0 1 1 1 0 0 1 0]
--------------------------------------------------
Output: [1 1 1 0 0 1 0 1 1 1 0 0 1 0 1]