Course 2 Week 2 Assignment Viterbi Backward - 3 Tests passed 1 Test failed

[VINOD_BAJAJ]

True, if you print out pred[-1] after the first and the second loop, you will see that somewhere pred[-1] got overwritten in the second for loop.

I had the same problem. Everything I implemented was correct.
I observed that the pred[-1] was correctly assigned (with “–s–”) in the first loop. But, after the second loop pred[-1] is “#”. I could not find how pred[-1] got overwritten.
This is the problem you also faced.
How I solved it:
store pred[m - 1] in some variable (say temp) and then before returning replace pred[-1] with temp.
It worked.

[Dong_An]

It seems to me that in the loop of step 2, we cannot double update the last element of z to avoid the error.

[AbdulRahman_Armashi]

@Mubsi
please i need you to check Ex7 , i have the same problem
note book id is: pldrnywv

thanks

[manish_singh]

Hi am getting and test failed in Viterbi backward algorithm my lab ID: lbnwniwtrphg

[Mubsi]

Hi @manish_singh,

Your pred[m - 1] is incorrect.

Best,
Mubsi

[Arunava_Chakraborty]

Hi @Mubsi
I have the same issue, I tried changing the range of the second for loop but in both cases, I got the same error for the mismatch of the last character in a particular test case.

My lab id : rpscoyintppy
Please check.

Thanks in advance.

[Mubsi]

@Arunava_Chakraborty

rpscoyintppy

Hi @Arunava_Chakraborty,

There are many things wrong with your implementation of the exercise, particularly the ranges you have selected. I’ll DM you with more details.

Best,
Mubsi

[Sujan_Kapali1]

Hello sir @Mubsi, I am getting same error with my work, I am getting ‘#’ instead of ‘–s–’ . Can you please help me fix it? My lab id is: izslfbkjahyx. Thank you!

[Mubsi]

Hi @Sujan_Kapali1,

Let me DM you regarding this.

[Agrim_Jain]

Hi Sir @Mubsi, I am facing the same issue. Please help me fix it. My lab id is: mnwiiywkprgv

[Sonu_Chhabra]

Hi @Mubsi,
I am also facing the same issue. Can you please take a look or guide me.
Lab Id: njljosvxdgtc

Thanks

[Mubsi]

@Mubsi

• In Ex 7, your first if statement doesn’t have the correct range.
• Similarly for the variable best_prob_for_last_word, your range is incorrect.
• Your variable pred[m - 1] is incorrect.

Hi @Agrim_Jain,

Other than the mistakes quoted above your:

• Second for loop has incorrect range and implementation
• pred[i - 1] is incorrect

Cheers,
Mubsi

[Mubsi]

Hi @Sonu_Chhabra,

Your pred[m - 1], pos_tag_for_word_i, z[i - 1] and pred[i - 1] are incorrect.

Cheers,
Mubsi

[Agrim_Jain]

Sir, It would be really helpful if you could suggest corrections as I am unable to rectify the mistake despite trying many times.

[Elemento]

Hey @Agrim_Jain,
Can you please DM me your current implementation of the viterbi_backward function, so that I can take a look and try to help you out.

Cheers,
Elemento

[NIKHILM710]

I am also facing the same issue. 3 tests passed and 1 test failed

[NIKHILM710]

{Moderator’s Edit: Please don’t mention Lab ID unless explicitly asked for}

[Elemento]

Hey @NIKHILM710,
Welcome to the community. As you can see it’s a long thread and many common mistakes have already been discussed regarding the implementation of this function. So, can you please go through them once, and see if either of these help.

Cheers,
Elemento

[NIKHILM710]

Hi Elemento,
I visited the thread yesterday. But it didn’t helped me to find out error in Viterbi backward function.
{Moderator’s Edit: Please don’t mention Lab ID unless explicitly asked for}

Thanks,
Nkhil

[Elemento]

Hey @NIKHILM710,
The mentors don’t have the access to your labs, only Mubsi has that. Can you please DM me the implementation of your viterbi_backward function?

Cheers,
Elemento