# How to find the difference today's SlowVSI and yesterday's SlowVSI?

#### chaser2009

##### New member
Hello,

I am new to thinkorswim and I want to make a custom code for my charts. I am trying to find a way to find the difference between today's SlowVSI and yesterday's SlowVSI (today - yesterday).

Also, I want to try and find a way to know when the SlowVSI crosses 50. Is there a way to write a script for it to send an alert when a chart crosses 50 on the SlowVSI? (preferably a SMS alert)

Thank you.

#### tomsk

##### Well-known member
VIP
I don't know what a SlowVSI is, but typically the day you get the difference between the values of say today's close and yesterday's close would be close - close[1]. You can apply the same logic to your SlowVSI indicator

#### chaser2009

##### New member
I don't know what a SlowVSI is, but typically the day you get the difference between the values of say today's close and yesterday's close would be close - close[1]. You can apply the same logic to your SlowVSI indicator
Thank you for helping!

#### chaser2009

##### New member
Hi,

I want to plot LRR if Up is 1 and Dn is -1, others is 0. I am new, I can't figure out how to code it. help please!

Thanks.

Code:
``````input emaLength = 6;
input vsiLength = 14;

def ema = ExpAverage(close, emaLength);
def avgVolUp = WildersAverage(if close > ema then volume else 0, vsiLength);
def avgVolDown = WildersAverage(if close < ema then volume else 0, vsiLength);

def SlowVSI = if avgVolUp + avgVolDown == 0 then 50 else 100 * avgVolUp / (avgVolUp + avgVolDown);

def up=slowvsi crosses above slowvsi[1];
def dn=slowvsi crosses below slowvsi[1];

plot LRR = if up then 1 else 0;
LRR.SetDefaultColor(GetColor(1));``````

Last edited by a moderator:

#### tomsk

##### Well-known member
VIP
@chaser2009 - I have modified your code so that it plots LRR with 1 if the variable "up" evaluates to a boolean true, and plots -1 if the variable "dn" evaluates to a boolean true. Otherwise it just plots 0. Also, you'd want this to be in a lower study. Here's your modified study

declare lower;

input emaLength = 6;
input vsiLength = 14;

def ema = ExpAverage(close, emaLength);
def avgVolUp = WildersAverage(if close > ema then volume else 0, vsiLength);
def avgVolDown = WildersAverage(if close < ema then volume else 0, vsiLength);

def SlowVSI = if avgVolUp + avgVolDown == 0 then 50 else 100 * avgVolUp / (avgVolUp + avgVolDown);

def up=slowvsi crosses above slowvsi[1];
def dn=slowvsi crosses below slowvsi[1];

plot LRR = if up then 1 else if dn then -1 else 0;
LRR.SetDefaultColor(GetColor(1));

#### chaser2009

##### New member
Hi,

I want to plot LRR if Up is 1 and Dn is -1, others is 0. I am new, I can't figure out how to code it. help please!

Thanks.

Code:
``````input emaLength = 6;
input vsiLength = 14;

def ema = ExpAverage(close, emaLength);
def avgVolUp = WildersAverage(if close > ema then volume else 0, vsiLength);
def avgVolDown = WildersAverage(if close < ema then volume else 0, vsiLength);

def SlowVSI = if avgVolUp + avgVolDown == 0 then 50 else 100 * avgVolUp / (avgVolUp + avgVolDown);

def up=slowvsi crosses above slowvsi[1];
def dn=slowvsi crosses below slowvsi[1];

plot LRR = if up then 1 else 0;
LRR.SetDefaultColor(GetColor(1));``````

Thank you very much!

could you help to write if Up, alert sent SMS to the mobile?

#### tomsk

##### Well-known member
VIP
For SMS to be sent to your mobile, you would have to use MarketWatch Alerts. MarketWatch Alerts have to be individually set or set as part of a Dynamic WatchList. Probably best to contact the trade desk for assistance on platform related queries so they can walk you through the specifics step by step

#### chaser2009

##### New member
For SMS to be sent to your mobile, you would have to use MarketWatch Alerts. MarketWatch Alerts have to be individually set or set as part of a Dynamic WatchList. Probably best to contact the trade desk for assistance on platform related queries so they can walk you through the specifics step by step
Thank you very much!

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