how can I plot transconductance of a V-I circuitry from claculator？

Hello,

I got a problem to plot Gt from my circuit. I tried to plot it from wave function of calcualtor but it shows "nil" from expression...Thanks in advance！

奶奶的 你不会说中文啊 鸟语懒得看

have u saved the current data?

Yes, I did.  Actually, I did get Gt plot once but most of time I couldn't see wave() from the window of calculator. I only see those expressions of traces. And it normally accompanies with question mark in those expressions. I wonder is there anything related to settings? The system I am using is IC610+MMSIM61.
Thanks for your replying and do you have any idea on this issue?
By the way, my work laptop doesn't have chinese keyboard so I can't type chinese.

你可以先确定一下你想看的电流是否真的能plot.如果可以说明你的公式表达有错误。仔细看看你的公式说不定就是因为netname变了导致的

要测Gm? 是一个mos管吗?
仿真电路能否贴下?

    Thanks for your replying. I know how to plot it now.  I was going to plot a Gm of a V-I converter and check its performance. Thanks guys！

在calculator里选info-》op,选你要看的管子的gm,这样可以看到某个工作点下的gm, 再跑一个parametric的仿真，就可以看到不同工作点下的gm, 这样就是图形了。

So, you can share your experience with us now.

Share, share, share！ May be new one way for another.
It's the final meaning of fourm.

I aimed to get the Gm wave of a V-I converter. The equation of Gm is d(I2-I1)/d(V1-V2). ‘d’ means differential here. So there are several steps to plot the waveform of transconductance.  
1)        Simulate your circuit first.
2)        Go to results->direct plot->Main form-> select current-> select differential terminals I1 and I2 (positive/negative)
3)        Do the same settings like last step. Select voltage -> select differential terminals V1 and V2.
4)        To get the differential current you need to plot I1 and I2 separately in ADE. Go to outputs -> to be plotted -> select on the schematic I1 and I2
5)        Plot Gm from calculator: click the expression of item 2) from ViVA window -> calculator ->check if there is ‘wave_x()’ on the screen -> select ‘deriv’
Click the expression of item 3) from ViVA window -> calculator ->check if there is ‘wave_x+1()’ on the screen -> select ‘deriv’
Then select ‘/’ (you will see expression: deriv (I2-I1)/ deriv (V1-V2) on the calculator screen)….click plot -> you will see the Gm wave

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