[ns] Fw: info.

[kidA]

mohamed saad wrote:
a salamo alikom
> how are dear 
> when i run this script: 
> set val(chan) Channel/WirelessChannel 
> set val(prop) Propagation/TwoRayGround 
> set val(netif) Phy/WirelessPhy 
> set val(mac) Mac/802_11 
> set val(ifq) Queue/DropTail/PriQueue 
> set val(ll) LL 
> set val(ant) Antenna/OmniAntenna 
> set val(x) 1000 ;# X dimension of the topography 
> set val(y) 1000 ;# Y dimension of the topography 
> set val(ifqlen) 50 ;# max packet in ifq 
> set val(seed) 0.0 
> set val(adhocRouting) SEAD # Same code will be implemented for Ariadne 
> # by changing the protocol to Ariadne. 
> # The source code for SEAD and Ariadne was taken from 
> # http://www.monarch.cs.rice.edu/software.html 
> # By Yih-Chun Hu, David B. Johnson, and Adrian Perrig. 
> set val(nn) 20 ;# how many nodes are simulated 
> set val(sc) "scen-20-test" 
> set val(cp) "cbr-20-test" 
> set val(stop) 800.0 ;# simulation time 
> # ===================================================================== 
> # Core Program 
> # ===================================================================== 
> #How many packets have been received by the traffic links? 
> #Get the current time 
> set now [$ns_ now] 
> set bw1 [$sink1 set bytes_] 
> set bw2 [$sink2 set bytes_] 
> if $now = 25 
> #Calculate the packets (in kbytes/s) and write it to the trace file 
> puts $sead1 "$now [expr $[ (bw2/1024)/512) / (bw1/1024)/512) ]" 
> else 
> puts $sead1 "$now [expr $ (bw2/1024)/512) / (bw1/1024)/512) ]" 
> #Reset the bytes_ values on the traffic sinks 
> $sink1 set bytes_ 0 
> $sink2 set bytes_ 0 
> #Re-schedule the procedure 
> $ns_ at [expr $now+$now] "record" 
> } 
>   
> appear this error: 
>   
> can't read "ns_": no such variable 
>     while executing 
> "$ns_ now" 
>     invoked from within 
> set now [$ns_ now]" 
>   
> what i do to solve this error?

You have to declare and set the "ns_" variable.
At the beginning of your script just add:

set ns_   [new Simulator]

Loris
-- 
"let me take you down, 'cos i'm going to Strawberry Fields."

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