Hi All,

I am very new to using such platforms, so apologies if I don’t phrase my question properly -

Facing an issue for several hours now when I run code cell 20 in Week 2 Assignment. I receive the following error message :

```
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-20-9408a3dffbf6> in <module>
1 from public_tests import *
2
----> 3 model_test(model)
~/work/release/W2A2/public_tests.py in model_test(target)
127 assert type(d['costs']) == list, f"Wrong type for d['costs']. {type(d['costs'])} != list"
128 assert len(d['costs']) == 1, f"Wrong length for d['costs']. {len(d['costs'])} != 1"
--> 129 assert np.allclose(d['costs'], expected_output['costs']), f"Wrong values for d['costs']. {d['costs']} != {expected_output['costs']}"
130
131 assert type(d['w']) == np.ndarray, f"Wrong type for d['w']. {type(d['w'])} != np.ndarray"
AssertionError: Wrong values for d['costs']. [array(0.15900538)] != [array(0.69314718)]
```

I have checked my formula to calculate cost and I believe it is correct. I have also passed all test up until this point (including the earlier cost calculation which matches the expected output).

Furthermore , when I run the next cell to train the model , I get the expected accuracy figures :

```
Cost after iteration 0: 0.693147
Cost after iteration 100: 0.584508
Cost after iteration 200: 0.466949
Cost after iteration 300: 0.376007
Cost after iteration 400: 0.331463
Cost after iteration 500: 0.303273
Cost after iteration 600: 0.279880
Cost after iteration 700: 0.260042
Cost after iteration 800: 0.242941
Cost after iteration 900: 0.228004
Cost after iteration 1000: 0.214820
Cost after iteration 1100: 0.203078
Cost after iteration 1200: 0.192544
Cost after iteration 1300: 0.183033
Cost after iteration 1400: 0.174399
Cost after iteration 1500: 0.166521
Cost after iteration 1600: 0.159305
Cost after iteration 1700: 0.152667
Cost after iteration 1800: 0.146542
Cost after iteration 1900: 0.140872
train accuracy: 99.04306220095694 %
test accuracy: 70.0 %
```

Really confused why code cell 20 when calling the model function gives me the wrong value for cost error. Any assistance in this regard will be really appreciated!

Thanks.