My `version`

output in RStudio,

```
platform x86_64-w64-mingw32
arch x86_64
os mingw32
system x86_64, mingw32
status
major 4
minor 0.4
year 2021
month 02
day 15
svn rev 80002
language R
version.string R version 4.0.4 (2021-02-15)
nickname Lost Library Book
```

**My MRE:**

```
N = 32;
dx = 1.0;
m = 1;
for (i in 1:5) {
c[i] = 0.5*(1+sin(2*pi*m*i*dx/N));
}
plot(c)
par(new=TRUE)
halfN = N/2;
delk = 2*pi/N;
dt = 0.5;
for (m in 1:80) {
chat = fft(c);
for (i in 1:N) {
if ((i-1) <= halfN) k <-
(i-1)*delk;
if ((i-1) > halfN) k <-
(i-1-N)*delk;
k2 = k*k;
chat[i] = chat[i]/(1 + k2*dt);
}
c = fft(fft(c), inverse = TRUE)/length(c);
}
plot(c)
```

I get an empty output plot as follows:

I am expecting to get the sinusoidal wave as initialized in the 1st for loop & `fft()`

of the same to solve the diffusion equation.

Where am I going wrong with the code