Excel Table Madness!!

[CrazyAMonkey]

Hello again all, i have a new and annoying problem.

I have created a scatter graph to compare 2 sets of values. On Y i have stress and on the X i have strain (irrelevant i know, just setting the scene )

my info table is thus,

<table style="border-collapse: collapse; width: 308pt;" width="409" border="0" cellpadding="0" cellspacing="0"><col style="width: 53pt;" width="70"> <col style="width: 98pt;" width="130"> <col style="width: 81pt;" width="108"> <col style="width: 76pt;" width="101"> <tbody><tr style="height: 16.5pt;" height="22"> <td colspan="2" class="xl71" style="border-right: 1pt solid black; height: 16.5pt; width: 151pt;" width="200" height="22">Test Data For Sample Y</td> <td colspan="2" class="xl71" style="border-right: 1pt solid black; border-left: medium none; width: 157pt;" width="209">Results For Sample Y</td> </tr> <tr style="height: 19.5pt;" height="26"> <td class="xl68" style="height: 19.5pt; width: 53pt;" width="70" height="26">Load (N)</td> <td class="xl69" style="width: 98pt;" width="130">Extension (mm)</td> <td class="xl69" style="width: 81pt;" width="108">Stress (N/m²)</td> <td class="xl69" style="width: 76pt;" width="101">Strain</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">2000</td> <td class="xl67" style="width: 98pt;" width="130">0.6</td> <td class="xl70" style="width: 81pt;" width="108">100.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">1.09E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">4000</td> <td class="xl67" style="width: 98pt;" width="130">0.8</td> <td class="xl70" style="width: 81pt;" width="108">200.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">1.45E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">6000</td> <td class="xl67" style="width: 98pt;" width="130">1</td> <td class="xl70" style="width: 81pt;" width="108">300.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">1.82E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">8000</td> <td class="xl67" style="width: 98pt;" width="130">1.18</td> <td class="xl70" style="width: 81pt;" width="108">400.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">2.15E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">9400</td> <td class="xl67" style="width: 98pt;" width="130">1.3</td> <td class="xl70" style="width: 81pt;" width="108">470.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">2.36E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">9200</td> <td class="xl67" style="width: 98pt;" width="130">1.5</td> <td class="xl70" style="width: 81pt;" width="108">460.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">2.73E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">9200</td> <td class="xl67" style="width: 98pt;" width="130">1.6</td> <td class="xl70" style="width: 81pt;" width="108">460.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">2.91E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">10000</td> <td class="xl67" style="width: 98pt;" width="130">1.75</td> <td class="xl70" style="width: 81pt;" width="108">500.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">3.18E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">11000</td> <td class="xl67" style="width: 98pt;" width="130">2.1</td> <td class="xl70" style="width: 81pt;" width="108">550.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">3.82E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">12000</td> <td class="xl67" style="width: 98pt;" width="130">2.4</td> <td class="xl70" style="width: 81pt;" width="108">600.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">4.36E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">14000</td> <td class="xl67" style="width: 98pt;" width="130">5</td> <td class="xl70" style="width: 81pt;" width="108">700.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">9.09E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">12000</td> <td class="xl67" style="width: 98pt;" width="130">7.2</td> <td class="xl70" style="width: 81pt;" width="108">600.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">13.09E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">10000</td> <td class="xl67" style="width: 98pt;" width="130">7.25</td> <td class="xl70" style="width: 81pt;" width="108">500.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">13.18E-3</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 53pt;" width="70" height="22">8000</td> <td class="xl67" style="width: 98pt;" width="130">7.27</td> <td class="xl70" style="width: 81pt;" width="108">400.00E+6</td> <td class="xl70" style="width: 76pt;" width="101">13.22E-3
</td> </tr> </tbody></table>

As you can see the values of strain are ever increasing, however whenever i make the graph of stress Vs strain i get a negative going tail for the last two values (i.e. graph is saying strain is decreasing).

I can not understand what is happening with it?!

I know this has to be a quick fix and my error, please someone put me out of my misery!!

 

[VoG]

The last 3 values have quite different stress but very similar strain.

 

[CrazyAMonkey]

There is quite a marked inflection even though the numbers are actually increasing. I think i know what you mean, i.e. you might not notice the graph moving forward due to the small movement. That i could handle happily, this is definitely showing a reverse in direction though which i cannot accept

Sorry if i have caught the wrong end of the stick

Picture Posted

 

[CrazyAMonkey]

 

[VoG]

The problem data is here I believe

 

[CrazyAMonkey]

ok, is this an understanding problem between maths and excel then?

Here are the values formatted specially and normally :

<table style="border-collapse: collapse; width: 152pt;" width="202" border="0" cellpadding="0" cellspacing="0"><col style="width: 76pt;" width="101" span="2"> <tbody><tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 76pt;" width="101" height="22">4.36E-3</td> <td class="xl67" style="width: 76pt;" width="101">0.004363636</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 76pt;" width="101" height="22">9.09E-3</td> <td class="xl67" style="width: 76pt;" width="101">0.009090909</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 76pt;" width="101" height="22">13.09E-3</td> <td class="xl67" style="width: 76pt;" width="101">0.013090909</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 76pt;" width="101" height="22">13.18E-3</td> <td class="xl67" style="width: 76pt;" width="101">0.013181818</td> </tr> <tr style="height: 16.5pt;" height="22"> <td class="xl66" style="height: 16.5pt; width: 76pt;" width="101" height="22">13.22E-3</td> <td class="xl67" style="width: 76pt;" width="101">0.013218182</td> </tr> </tbody></table>
I thought about this myself earlier and got rid of the exponential terms to leave pure decimals. The graph still looked identical.

The value IS increasing so why does the line not continue to the right as i would expect and dearly love it to?

 

[CrazyAMonkey]

OK, i got it.

Its the bloomin curve drawn by Excel. Just held a pen up to get a straight edge and it DOES move forward!! Really sorry for wasting your time and for possibly testing your patience VoG, much appreciated though, you made me look closer and from a different angle.

Thank you VoG!

Ewan