In purchase.order.line i have added some fields and their respective inverse method to change the corresponding fields 

class PurchaseOrderInherit(models.Model):
    _inherit = "purchase.order.line"

   mrp = fields.Float("MRP") 
	​margin = fields.Float("Mark Down%", compute="_compute_margin", inverse="_inverse_margin", digits='Product Price', store=True,
                          help="(MRP Excl. - Cost Excl.) / MRP Excl.")
    margin_up = fields.Float("Mark Up %", compute="_compute_margin", inverse="_inverse_margin_up", digits='Product Price', store=True,
                          help="(MRP Excl. - Cost Excl.) / Cost Excl.")
    margin_status = fields.Char("Change in Margin%", compute="_compute_margin_status", store=True)
    margin_prev = fields.Float("Margin Prev %", store=True)
    disc_amount = fields.Float("Disc. Amount", compute="_compute_disc_amount", inverse="_inverse_disc_amount",
                               help="Discount Amount for Total Quantity", store="True", digits='Product Price')

    @api.depends("mrp", "product_qty", "price_subtotal", "product_id")
    def _compute_margin(self):
        for rec in self:
            if rec.mrp and rec.price_subtotal:
                base_amount = self._get_tax_amount(rec.product_id, rec.mrp) * rec.product_qty
                rec.margin = (base_amount - rec.price_subtotal) / base_amount * 100 if base_amount else 0
                rec.margin_up = (base_amount - rec.price_subtotal) / rec.price_subtotal * 100 if rec.price_subtotal else 0
            else:
                rec.margin = False
                rec.margin_up = False

    @api.onchange('margin_up')
    def _inverse_margin_up(self):
        for rec in self:
            if rec.product_id and rec.margin_up not in (False, 0):
                if rec.price_subtotal:
                    base_amount = rec.price_subtotal * (1 + rec.margin_up / 100)
                    rec.mrp = round(rec.product_qty and self._get_mrp_from_base_amount(rec.product_id, base_amount) / rec.product_qty)

    @api.onchange('margin')
    def _inverse_margin(self):
        for rec in self:
            base_amount = self._get_tax_amount(rec.product_id, rec.mrp)
            if base_amount != 0 and rec.discount != 100:
                rec.price_unit = (base_amount * (1 - rec.margin / 100)) / (1 - rec.discount / 100)

    def _get_mrp_from_base_amount(self, product, base_amount):
        taxes = product.taxes_id.filtered(
            lambda x: x.company_id.id == self.env.company.id
                      or x.company_id.id == self.env.company.parent_id.id
        )
        tax_amount = sum(taxes.mapped('amount'))
        mrp = base_amount * (1 + tax_amount / 100)
        return mrp

    def _get_tax_amount(self, product, price):
        taxes_id = product.taxes_id.filtered(
            lambda x: x.company_id.id == self.env.company.id
            or x.company_id.id == self.env.company.parent_id.id
        )
        if taxes_id:
            amount = taxes_id.compute_all(
                price, product=product, partner=self.env["res.partner"]
            )
            amount = amount["total_excluded"]
        else:
            amount = price
        return amount

    # update margin status
    @api.depends("mrp", "price_unit")
    def _compute_margin_status(self):
        for rec in self:
            margin_prev = False
            if rec.product_id.id:
                margin_prev = (
                    self.env["purchase.order.line"]
                    .search(
                        [
                            ("product_id", "=", rec.product_id.id),
                            ("partner_id", "=", rec.partner_id.id),
                            ("order_id", "!=", rec.order_id._origin.id),
                            ("company_id", '=', self.env.company.id),
                        ],
                        order="create_date desc",
                        limit=1,
                    )
                    .margin
                )
                rec.margin_prev = margin_prev
            if margin_prev == False:
                rec.margin_status = "NA"
            elif rec.margin > margin_prev:
                rec.margin_status = str(round(rec.margin - margin_prev, 1)) + " ⇑"
            elif rec.margin == margin_prev:
                rec.margin_status = str(round(rec.margin - margin_prev, 1)) + " ⇔"
            elif rec.margin                 rec.margin_status = str(round(rec.margin - margin_prev, 1)) + " ⇓"

    @api.depends('discount')
    def _compute_disc_amount(self):
        for rec in self:
            if rec.discount:
                rec.disc_amount = rec.price_unit * rec.product_qty * (rec.discount / 100)
            else:
                rec.disc_amount = 0.0

    @api.onchange('disc_amount')
    def _inverse_disc_amount(self):
        for rec in self:
            if rec.price_unit and rec.product_qty:
                rec.discount = (rec.disc_amount / (rec.price_unit * rec.product_qty)) * 100

I have added all the inverse function as api.onchange() but it triggers whenever the field updates it results some unwanted values is there anything i can do
if anyone knows help me